Chapter 37

VALUATION AND ANALYSIS OF CARBIDE

The sale and purchase of calcium carbide in this country will, under existing conditions, usually be conducted in conformity with the set of regulations issued by the British Acetylene Association, of which a copy, revised to date, is given below:

"REGULATIONS AS TO CARBIDE OF CALCIUM."

1. The carbide shall be guaranteed by the seller to yield, when broken to standard size, _i.e._, in lumps varying from 1 to 2-1/2 inches or larger, not less than 4.8 cubic feet per lb., at a barometric pressure of 30 inches and temperature of 60° Fahr. (15.55° Centigrade). The actual gas yield shall be deemed to be the gas yield ascertained by the analyst, plus 5 per cent.

"Carbide yielding less than 4.8 cubic feet in the sizes given above shall be paid for in proportion to the gas yield, _i.e._, the price to be paid shall bear the same relation to the contract price as the gas yield bears to 4.8 cubic feet per lb.

"2. The customer shall have the right to refuse to take carbide yielding in the sizes mentioned above less than 4.2 cubic foot, per lb., and it shall lie, in case of refusal and as from the date of the result, of the analysis being made known to either party, at the risk and expense of the seller.

"3. The carbide shall not contain higher figures of impurities than shall from time to time be fixed by the Association.

"4. No guarantee shall be given for lots of less than 3 cwt., or for carbide crushed to smaller than the above sizes.

"5. In case of dispute as to quality, either the buyer or the seller shall have the right to have one unopened drum per ton of carbide, or part of a ton, sent for examination to one of the analysts appointed by the Association, and the result of the examination shall be held to apply to the whole of the consignment to which the drum belonged. "6. A latitude of 5 per cent, shall be allowed for analysis; consequently differences of 5 per cent. above or below the yields mentioned in 1 and 2 shall not be taken into consideration.

"7. Should the yield of gas be less than 4.8 cubic feet less 5 per cent., the carriage of the carbide to and from the place of analysis and the cost of the analysis shall be paid for by the seller. Should the yield be more than 4.8 cubic feet less 5 per cent., the carriage and costs of analysis shall be borne by the buyer, who, in addition, shall pay an increase of price for the carbide proportionate to the gas yield above 4.8 cubic feet plus 5 per cent.

"8. Carbide of 1 inch mesh and above shall not contain more than 5 per cent. of dust, such dust to be defined as carbide capable of passing through a mesh of one-sixteenth of an inch.

"9. The seller shall not be responsible for deterioration of quality caused by railway carriage in the United Kingdom, unless he has sold including carriage to the destination indicated by the buyer.

"10. Carbide destined for export shall, in case the buyer desires to have it tested, be sampled at the port of shipment, and the guarantee shall cease after shipment.

"11. The analyst shall take a sample of not less than 1 lb. each from the top, centre, and bottom of the drum. The carbide shall be carefully broken up into small pieces, due care being taken to avoid exposure to the air as much as possible, carefully screened and tested for gas yield by decomposing it in water, previously thoroughly saturated by exposure to acetylene for a period of not less than 48 hours.

"12. Carbide which, when properly decomposed, yields acetylene containing from all phosphorus compounds therein more than .05 per cent. by volume of phosphoretted hydrogen, may be refused by the buyer, and any carbide found to contain more than this figure, with a latitude of .01 per cent. for the analysis, shall lie at the risk and expense of the seller in the manner described in paragraph 2.

"The rules mentioned in paragraph 7 shall apply as regards the carriage and costs of analysis; in other words, the buyer shall pay these costs if the figure is below 0.05 per cent. plus 0.01 per cent., and the seller if the figure is above 0.05 per cent. plus 0.01 per cent.

"The sampling shall take place in the manner prescribed in paragraphs 5 and 11, and the analytical examination shall be effected in the manner prescribed by the Association and obtainable upon application to the Secretary."

* * * * *

The following is a translation of the corresponding rules issued by the German Acetylene Association (_Der Deutsche Acetylenverein_) in regard to business dealings in calcium carbide, as put into force on April 1, 1909:

"REGULATIONS OF THE GERMAN ACETYLENE ASSOCIATION FOR TRADE IN CARBIDE.

"_Price_.

"The price is to be fixed per 100 kilogrammes (= 220 lb.) net weight of carbide in packages containing about 100 kilogrammes.

"By packages containing about 100 kilogrammes are meant packages containing within 10 per cent. above or below that weight.

"The carbide shall be packed in gas- and water-tight vessels of sheet- iron of the strength indicated in the prescriptions of the carrying companies.

"The prices for other descriptions of packing must be specially stated.

"_Place of Delivery_.

"For consignment for export, the last European shipping port shall be taken as the place of delivery.

"_Quality_.

"Commercial carbide shall be of such quality that in the usual lumps of 15 to 80 mm. (about 3/5 to 3 inches) diameter it shall afford a yield of at least 300 litres at 15° C. and 760 mm. pressure of crude acetylene per kilogramme for each consignment (= 4.81 cubic feet at 60° F. and 30 inches per lb.). A margin of 2 per cent. shall be allowed for the analysis. Carbide which yields less than 300 litres per kilogramme, but not less than 270 litres (= 4.33 cubic feet) of crude acetylene per kilogramme (with the above-stated 2 per cent. margin for analysis) must be accepted by the buyer. The latter, however, is entitled to make a proportionate deduction from the price and also to deduct the increased freight charges to the destination or, if the latter is not settled at the time when the transaction is completed, to the place of delivery. Carbide which yields less than 270 litres of crude acetylene per kilogramme need not be accepted.

"Carbide must not contain more than 5 per cent. of dust. By dust is to be understood all which passes through a screen of 1 mm. (0.04 inch) square, clear size of holes.

"Small carbide of from 4 to 15 mm. (= 1/6 to 3/5 inch) in size (and intermediate sizes) must yield on the average for each delivery at least 270 litres at 15° C. and 760 mm. pressure of crude acetylene per kilogramme (= 4.33 cubic feet at 60° F. and 30 inches per lb.) A margin of 2 per cent. shall be allowed for the analysis. Small carbide of from 4 to 15 mm. in size (and intermediate sizes) which yields less than 270 litres but not less than 250 litres (= 4.01 cubic feet per lb.) of crude acetylene per kilogramme (with the above-stated 2 per cent. margin for analysis) must be accepted by the buyer. The latter, however, is entitled to make a proportionate deduction from the price and also to deduct the increased freight charges to the destination or, if the latter is not settled at the time when the transaction is completed, to the place of delivery. Small carbide of from 4 to 15 mm. in size (and intermediate sizes) which yields less than 250 litres per kilogramme need not be accepted.

"Carbide shall only be considered fit for delivery if the proportion of phosphoretted hydrogen in the crude acetylene does not amount to more than 0.04 volume per cent. A margin of 0.01 volume per cent. shall be allowed for the analysis for phosphoretted hydrogen. The whole of the phosphorus compounds contained in the gas are to be calculated as phosphoretted hydrogen.

"_Period for Complaints._

"An interval of four weeks from delivery shall be allowed for complaints for consignments of 5000 kilogrammes (= 5 tons) and over, and an interval of two weeks for smaller consignments. A complaint shall refer only to a quantity of carbide remaining at the time of taking the sample.

"_Determination of Quality._

"1. In case the parties do not agree that the consignee is to send to the analyst for the determination of the quality one unopened and undamaged drum when the consignment is less than 5000 kilogrammes, and two such drums when it is over 5000 kilogrammes, a sample for the purpose of testing the quality is to be taken in the following manner:

"A sample having a total weight of at least 2 kilogrammes (= 4.4 lb.) is to be taken. If the delivery to be tested does not comprise more than ten drums, the sample is to be taken from an unopened and undamaged drum selected at random. With deliveries of more than ten drums, the sample is to be drawn from not fewer than 10 per cent, of the lot, and from each of the unopened and undamaged drums drawn for the purpose not less than 1 kilogramme (= 2.2 lb.) is to be taken.

"The sampling is to be carried out by a trustworthy person appointed by the two parties, or by one of the experts regularly recognised by the German Acetylene Association, thus: Each selected drum, before opening, is to be turned over twice (to got rid of any local accumulation of dust) and the requisite quantity is to be withdrawn with a shovel (not with the hand) from any part of it. These samples are immediately shot into one or more vessels which are closed air- and water-tight. The lid is secured by a seal. No other description of package, such as cardboard cases, boxes, &c., is permissible.

"If there is disagreement as to the choice of a trustworthy person, each of the two parties is to take the required quantity, as specified above.

"2. The yield of gas and the proportion of phosphoretted hydrogen contained in it are to be determined by the methods prescribed by the German Acetylene Association. If there are different analyses giving non- concordant results, an analysis is to be made by the German Acetylene Association, which shall be accepted as final and binding.

"In cases, however, where the first analysis has been made in the Laboratory of the German Acetylene Association and arbitration is required, the decisive analysis shall be made by the Austrian Acetylene Association. If one of the parties prevents the arbitrator's analysis being carried out, the analysis of the other party shall be absolutely binding on him.

"3. The whole of the cost of sampling and analysis is to be borne by the party in the wrong."

* * * * *

The corresponding regulations issued by the Austrian Acetylene Association (_Der Oesterreichische Acetylenverein_) are almost identical with those of the German Association. They contain, however, provisions that the price is to include packing, that the carbide must not be delivered in lumps larger than the fist, that the sample may be sealed in a glass vessel with well-ground glass stopper, that the sample is to be transmitted to the testing laboratory with particulars of the size of the lots and the number of drums drawn for sampling, and that the whole of it is to be gasified in lots of upwards of 1 kilogramme (= 2.2 lb.) apiece.

In Italy, it is enacted by the Board of Agriculture, Commerce and Industry that by calcium carbide is to be understood for legal purposes also any other carbide, or carbide-containing mixture, which evolves acetylene by interaction with water. Also that only calcium carbide, which on admixture with water yields acetylene containing less than 1 per cent. of its volume of sulphuretted hydrogen and phosphoretted hydrogen taken together, may be put on the market.

It is evident from the regulations quoted that the determination of the volume of gas which a particular sample of calcium carbide is capable of yielding, when a given weight of it is decomposed under the most favourable conditions, is a matter of the utmost practical importance to all interested in the trafficking of carbide, _i.e._, to the makers, vendors, brokers, and purchasers of that material, as well as to all makers and users of acetylene generating plant. The regulations of the British Association do not, however, give details of the method which the analyst should pursue in determining the yield of acetylene; and while this may to a certain extent be advantageously left to the discretion of the competent analyst, it is desirable that the results of the experience already won by those who have had special opportunities for practising this branch of analytical work should be embodied in a set of directions for the analysis of carbide, which may be followed in all ordinary analyses of that material. By the adoption of such a set of directions as a provisional standard method, disputes as to the quantity of carbide will be avoided, while it will still be open to the competent analyst to modify the method of procedure to meet the requirements of special cases. It would certainly be unadvisable in the present state of our analytical methods to accept any hard and fast of rules for analysis for determining the quality of carbide, but it is nevertheless well to have the best of existing methods codified for the guidance of analysts. The substance of the directions issued by the German Association (_Der Deutsche Acetylenverein_) is reproduced below.

"METHODS FOR THE DETERMINATION OF TILE YIELD OF GAS FROM CALCIUM CARBIDE.

"The greatest precision is attained when the whole of the sample submitted to the analyst is gasified in a carbide-to-water apparatus, and the gas evolved is measured in an accurately graduated gasholder.

"The apparatus used for this analysis must not only admit of all the precautionary rules of gas-analytical work being observed, but must also fulfil certain other experimental conditions incidental to the nature of the analysis.

"(_a_) The apparatus must be provided with an accurate thermometer to show the temperature of the confining water, and with a pressure gauge, which is in communication with the gasholder.

"(_b_) The generator must either be provided with a gasholder which is capable of receiving the quantity of gas evolved from the whole amount of carbide, or the apparatus must be so constructed that it becomes possible with a gasholder which in not too large (up to 200 litres = say 7 cubic feet capacity) to gasify a larger amount of carbide.

"(_c_) The generator must be constructed so that escape of the evolved gas from it to the outer air is completely avoided.

"(_d_) The gasholder must be graduated in parts up to 1/4 per cent. of its capacity, must travel easily, and be kept, as far as may be in suspension by counterweighting.

"(_e_) The water used for decomposing the carbide and the confining water must be saturated, before use, with acetylene, and, further, the generator must, before the analysis proper, be put under the pressure of the confining (or sealing) liquid."

The following is a description of a typical form of apparatus corresponding with the foregoing requirements:

"The apparatus, shown in the annexed figure, consists of the generator A, the washer B, and the gasholder C.

"The generator A consists of a cylindrical vessel with sloping bottom, provided with a sludge outlet _a_, a gas exit-pipe _b_, and a lid _b'_ fastened by screws. In the upper part ten boxes _c_ are installed for the purpose of receiving the carbide. The bottoms of those boxes are flaps which rest through their wire projections on a revolvable disc _d_, which is mounted on a shaft _l_. This shaft passes through a stuffing-box to the outside of the generator and can be rotated by moans of the chains _f_, the pulleys _g_ and _h_, and the winch _i_. Its rotation causes rotation of the disc _d_. The disc _d_, on which the bottoms of the carbide- holders are supported, is provided with a slot _e_. On rotating the disc, on which the supporting wires of the bottoms of the carbide-holders rest, the slot is brought beneath these wires in succession; and the bottoms, being thus deprived of their support, drop down. It is possible in this way to effect the discharge of the several carbide-holders by gradual turning of the winch _i_.

"The washer B is provided with a thermometer _m_ passing through a sound stuffing-box and extending into the water.

"The gasholder C is provided with a scale and pointer, which indicate how much gas there is in it. It is connected with the pressure-gauge _n_, and is further provided with a control thermometer _o_. The gas exit-pipe _q_ can be shut off by a cock. There is a cock between the gasholder and the washer for isolating one from the other.

"The dimensions of the apparatus are such that each carbide-holder can contain readily about half a kilogramme (say l lb.) of carbide. The gasholder is of about 200 litres (say 7 cubic feet) capacity; and if the bell is 850 mm. (= 33-1/2 inches) high, and 550 mm. (= 21-1/2 inches) in diameter it will admit of the position being read off to within half a litre (say 0.02 cubic foot)."

The directions of the German Association for sampling a consignment of carbide packed in drums each containing 100 kilogrammes (say 2 cwt.) have already been given in the rules of that body. They differ somewhat from those issued by the British Association (_vide ante_), and have evidently been compiled with a view to the systematic and rapid sampling of larger consignments than are commonly dealt with in this country. Drawing a portion of the whole sample from every tenth drum is substantially the same as the British Association's regulations for cases of dispute, viz., to have one unopened drum (_i.e._, one or two cwt.) per ton of carbide placed at the analyst's disposal for sampling. Actually the mode of drawing a portion of the whole sample from every tenth vessel, or lot, where a large number is concerned, is one which would naturally be adopted by analysts accustomed to sampling any other products so packed or stored, and there in no reason why it should be departed from in the case of large consignments of carbide. For lots of less than ten drums, unless there is reason to suspect want of uniformity, it should usually suffice to draw the sample from one drum selected at random by the sampler. The analyst, or person who undertakes the sampling, must, however, exercise discretion as to the scheme of sampling to be followed, especially if want of uniformity of the several lots constituting the consignment in suspected. The size of the lumps constituting a sample will be referred to later.

The British Association's regulations lead to a sample weighing about 3 lb. being obtained from each drum. If only one drum is sampled, the quantity taken from each position may be increased with advantage so as to give a sample weighing about 10 lb., while if a large number of drums is sampled, the several samples should be well mixed, and the ordinary method of quartering and re-mixing followed until a representative portion weighing about 10 lb. remains.

A sample representative of the bulk of the consignment having been obtained, and hermetically sealed, the procedure of testing by means of the apparatus already described may be given from the German Association's directions:

"The first carbide receptacle is filled with 300 to 400 grammes (say 3/4 lb.) of any readily decomposable carbide, and is hung up in the apparatus in such a position with regard to the slot _e_ on the disc _d_ that it will be the first receptacle to be discharged when the winch _i_ is turned. The tin or bottle containing the sample for analysis is then opened and weighed on a balance capable of weighing exactly to 1/2 gramme (say 10 grains). The carbide in it is then distributed quickly, and as far as may be equally, into the nine remaining carbide receptacles, which are then shut and hung up quickly in the generator. The lid _b'_ is then screwed on the generator to close it, and the empty tin or bottle, from which the sample of carbide has been removed, is weighed.

"The contents of the first carbide receptacle are then discharged by turning the winch _i_. Their decomposition ensures on the one hand that the sealing water and the generating water are saturated with acetylene, and on the other hand that the dead space in the generator is brought under the pressure of the seal, so that troublesome corrections which would otherwise be entailed are avoided. After the carbide is completely decomposed, but not before two hours at least have elapsed, the cock _p_ is shut, and the gasholder is run down to the zero mark by opening the cock _q_. The cock _q_ is then shut, _p_ is opened, and the analytical examination proper is begun by discharging the several carbide receptacles by turning the winch _i_. After the first receptacle has been discharged, five or ten minutes are allowed to elapse for the main evolution of gas to occur, and the cock _p_ is then shut. Weights are added to the gasholder until the manometer _n_ gives the zero reading; the position of the gasholder C is then read off, and readings of the barometer and of the thermometer _o_ are made. The gasholder is then emptied down to the zero mark by closing the cock _p_ and opening _q_. When this is done _q_ is closed and _p_ is opened, and the winch _i_ is turned until the contents of the next carbide receptacle are discharged. This procedure is followed until the carbide from the last receptacle has been gasified; then, after waiting until all the carbide has been decomposed, but in any case not less than two hours, the position of the gasholder is read, and readings of the barometer and thermometer are again taken. The total of the values obtained represents the yield of gas from the sample examined."

The following example is quoted:

Weight of the tin received, with its contained | carbide . . . . . ._| = 6325 grammes. Weight of the empty tin . . . . = 1485 " _______ Carbide used . . . = 4840 " = 10670 lb.

The carbide in question was distributed among the nine receptacles and gasified. The readings were:

________________________________________________ | | | | | | No. | Litres. | Degrees C. | Millimetres. | |______|__________|______________|_______________| | | | | | | 1 | 152.5 | 13 | 762 | | 2 | 136.6 | " | " | | 3 | 138.5 | " | " | | 4 | 161.0 | " | " | | 5 | 131.0 | " | " | | 6 | 182.5 | 13.5 | " | | 7 | 146.0 | " | " | | 8 | 163.0 | 14.0 | " | | 9 | 178.5 | " | " | |______|__________|______________|_______________|

After two hours, the total of the readings was 1395.0 litres at 13.5° C. and 762 mm., which is equivalent to 1403.7 litres (= 49.57 cubic feet) at 15° C. and 760 mm. (or 60° F. and 30 inches; there is no appreciable change of volume of a gas when the conditions under which it is measured are altered from 15° C. and 760 mm. to 60° F. and 30 inches, or _vice versâ_).

The yield of gas from this sample is therefore 1403.7/4.840 = 290 litres at 15° C. and 760 mm. per kilogramme, or 49.57/10.67 = 4.65 cubic feet at 60° F. and 30 inches per pound of carbide. The apparatus described can, of course, be used when smaller samples of carbide only are available for gasification, but the results will be less trustworthy if much smaller quantities than those named are taken for the test.

Other forms of carbide-to-water apparatus may of course be devised, which will equally well fulfil the requisite conditions for the test, viz., complete decomposition of the whole of the carbide without excessive rise of temperature, and no loss of gas by solution or otherwise.

An experimental wet gas-motor, of which the water-line has been accurately set (by means of the Gas Referees' 1/12 cubic foot measure, or a similar meter-proving apparatus), may be used in place of the graduated gasholder for measuring the volume of the gas evolved, provided the rate of flow of the gas does not exceed 1/6 cubic foot, or say 5 litres per minute. If the generation of gas is irregular, as when an apparatus of the type described above is used, it is advisable to insert a small gasholder or large bell-governor between the washer and the meter. The meter must be provided with a thermometer, according to the indications of which the observed volumes must be corrected to the corresponding volume at normal temperature.

If apparatus such as that described above is not available, fairly trustworthy results for practical purposes may be obtained by the decomposition of smaller samples in the manner described below, provided these samples are representative of the average composition of the larger sample or bulk, and a number of tests are made in succession and the results of individual tests do not differ by more than 10 litres of gas per kilogramme (or 0.16 cubic foot per pound) of carbide.

It is necessary at the outset to reduce large lumps of carbide in the sample to small pieces, and this must be done with as little exposure as possible to the (moist) air. Failing a good pulverising machine of the coffee-mill or similar type, which does its work quickly, the lumps must be broken as rapidly as possible in a dry iron mortar, which may with advantage be fitted with a leather or india-rubber cover, through a hole in which the pestle passes. As little actual dust as possible should be made during pulverisation. The decomposition of the carbide is best effected by dropping it into water and measuring the volume of gas evolved with the precautions usually practised in gas analysis. An example of one of the methods of procedure described by the German Association will show how this test can be satisfactorily carried out:

"A Woulff's bottle, _a_ in the annexed figure, of blown glass and holding about 1/4 litre is used as the generating vessel. One neck, about 15 mm. in internal diameter, is connected by flexible tubing with a globular vessel _b_, having two tubulures, and this vessel is further connected with a conical flask _c_, holding about 100 c.c. The other neck is provided with tubing _d_, serving to convey the gas to the inlet-tube, with tap _e_, of the 20-litre measuring vessel _f_, which is filled with water saturated with acetylene, and communicates through its lower tubulure with a similar large vessel _g_. The generating vessel _a_ is charged with about 150 c.c. of water saturated with acetylene. The vessel _f_ is filled up to the zero mark by raising the vessel _g_; the tap _e_ is then shut, and connexion is made with the tube _d_. Fifty grammes (or say 2 oz.) of the pulverised carbide are then weighed into the flask _c_ and this is connected by the flexible tubing with the vessel _b_. The carbide is then decomposed by bringing it in small portions at a time into the bulb _b_ by raising the flask _c_, and letting it drop from _b_ into the generating vessel _a_, after having opened the cock _e_ and slightly raised the vessel _f_. After the last of the carbide has been introduced two hours are allowed to elapse, and the volume of gas in _f_ is then read while the water stands at the same level in _f_ and _g_, the temperature and pressure being noted simultaneously."

A second, but less commendable method of decomposing the carbide is by putting it in a dry two-necked bottle, one neck of which is connected with _e_, and dropping water very slowly from a tap-funnel, which enters the other neck, on to the carbide. The generating bottle should be stood in water, in order to keep it cool, and the water should be dropped in at the rate of about 50 c.c. in one hour. It will take about three hours completely to gasify the 50 grammes of carbide under these conditions. The gas is measured as before.

Cedercreutz has carried out trials to show the difference between the yields found from large and small carbide taken from the same drum. One sample consisted of the dust and smalls up to about 3/5 inch in size, while the other contained large carbide as well as the small. The latter sample was broken to the same size as the former for the analysis. Tests were made both with a large testing apparatus, such as that shown in Fig. 22, and with a small laboratory apparatus, such as that shown in Fig. 23. The dust was screened off for the tests made in the large apparatus. Two sets of testings were made on different lots of carbide, distinguished below as "A" and "B," and about 80 grammes wore taken for each determination in the laboratory apparatus, and 500 grammes in the large apparatus. The results are stated in litres (at normal temperature and pressure) per kilogramme of carbide.

___________________________________________________________________ | | | | | | "A" | "B" | |_____________________________________________________|______|______| | | | | | Lot |Litres|Litres| | Small carbide, unscreened, in laboratory \ (1) | 276 | 267 | | apparatus . . . . . / (2) | 273 | 270 | | Average sample of carbide, unscreened, in \ (1) | 318 | 321 | | laboratory apparatus . . . / (2) | 320 | 321 | | Small carbide, dust freed, in large apparatus (1) | 288 | 274 | | Average sample of carbide, dust freed, in \ (2) | 320 | 322 | | large apparatus . . . . / | | | |_____________________________________________________|______|______|

As the result of the foregoing researches Cedercreutz has recommended that in order to sample the contents of a drum, they should be tipped out, and about a kilogramme (say 2 to 3 lb.) taken at once from them with a shovel, put on an iron base and broken with a hammer to pieces of about 2/5 inch, mixed, and the 500 grammes required for the analysis in the form of testing plant which he employs taken from this sample. Obviously a larger sample can be taken in the same manner. On the other hand the British and German Associations' directions for sampling the contents of a drum, which have already been quoted, differ somewhat from the above, and must generally be followed in cases of dispute.

Cedercreutz's figures, given in the above table, show that it would be very unfair to determine the gas-making capacity of a given parcel of carbide in which the lumps happened to vary considerably in size by analysing only the smalls, results so obtained being possibly 15 per cent. too low. This is due to two causes: first, however carefully it be stored, carbide deteriorates somewhat by the attack of atmospheric moisture; and since the superficies of a lump (where the attack occurs) is larger in proportion to the weight of the lump as the lump itself is smaller, small lumps deteriorate more on keeping than large ones. The second reason, however, is more important. Not being a pure chemical substance, the commercial material calcium carbide varies in hardness; and when it is merely crushed (not reduced altogether to powder) the softer portions tend to fall into smaller fragments than the hard portions. As the hard portions are different in composition from the soft portions, if a parcel is sampled by taking only the smalls, practically that sample contains an excess of the softer part of the original material, and as such is not representative. Originally the German Acetylene Association did not lay down any rules as to the crushing of samples by the analyst, but subsequently they specified that the material should be tested in the size (or sizes) in which it was received. The British Association, on the contrary, requires the sample to be broken in small pieces. If the original sample is taken in such fashion as to include large and small lumps as accurately as possible in the same proportion as that in which they occur in the main parcel, no error will be introduced if that sample is crushed to a uniform size, and then subdivided again; but a small deficiency in gas yield will be produced, which will be in the consumer's favour. It is not altogether easy to see the advantage of the British idea of crushing the sample over the German plan of leaving it alone; because the analytical generator will easily take, or its parts could be modified to take, the largest lumps met with. If the sample is in very large masses, and is decomposed too quickly, polymerisation of gas may be set up; but on the other hand, the crushing and re-sampling will cause wastage, especially in damp weather, or when the sampling has to be done in inconvenient places. The British Association requires the test to be made on carbide parcels ranging between 1 and 2-1/2 inches or larger, because that is the "standard" size for this country, and because no guarantee is to be had or expected from the makers as to the gas-producing capacity of smaller material. Manifestly, if a consumer employs such a form of generator that he is obliged to use carbide below "standard" size, analyses may be made on his behalf in the ordinary way; but he will have no redress if the yield of acetylene is less than the normal. This may appear a defect or grievance; but since in many ways the use of small carbide (except in portable lamps) is not advantageous--either technically or pecuniarily--the rule simply amounts to an additional judicious incentive to the adoption of apparatus capable of decomposing standard-sized lumps. The German and Austrian Associations' regulations, however, provide a standard for the quality of granulated carbide.

It has been pointed out that the German Association's direction that the water used in the testing should be saturated with acetylene by a preliminary decomposition of 1/2 kilogramme of carbide is not wholly adequate, and it has been suggested that the preliminary decomposition should be carried out twice with charges of carbide, each weighing not less than 1 per cent. of the weight of water used. A further possible source of error lies in the fact that the generating water is saturated at the prevailing temperature of the room, and liberates some of its dissolved acetylene when the temperature rises during the subsequent generation of gas. This error, of course, makes the yield from the sample appear higher than it actually is. Its effects may be compensated by allowing time for the water in the generator or gasholder to cool to its original temperature before the final reading is made.

With regard to the measurement of the temperature of the evolved gas in the bell gasholder, it is usual to assume that the reading of a thermometer which passes through the crown of the gasholder suffices. If the thermometer has a very long stem, so that the bulb is at about the mid-height of the filled bell, this plan is satisfactory, but if an ordinary thermometer is used, it is better to take, as the average temperature of the gas in the holder, the mean of the readings of the thermometer in the crown, and of one dipping into the water of the holder seal.

The following table gives factors for correcting volumes of gas observed at any temperature and pressure falling within its range to the normal temperature (60° F.) and normal barometric height (30 inches). The normal volume thus found is, as already stated, not appreciably different from the volume at 15° C. and 760 mm. (the normal conditions adopted by Continental gas chemists). To use the table, find the observed temperature and the observed reading of the barometer in the border of the table, and in the space where these vertical and horizontal columns meet will be found a number by which the observed volume of gas is to be multiplied in order to find the corresponding volume under normal conditions. For intermediate temperatures, &c., the factors may be readily inferred from the table by inspection. This table must only be applied when the gas is saturated with aqueous vapour, as is ordinarily the case, and therefore a drier must not be applied to the gas before measurement.

Hammerschmidt has calculated a similar table for the correction of volumes of gas measured at temperatures ranging from 0° to 30° C., and under pressures from 660 to 780 mm., to 15° C. and 760 mm. It is based on the coefficient of expansion of acetylene given in Chapter VI., but, as was there pointed out, this coefficient differs by so little from that of the permanent gases for which the annexed table was compiled, that no appreciable error results from the use of the latter for acetylene also. A table similar to the annexed but of more extended range is given in the "Notification of the Gas Referees," and in the text-book on "Gas Manufacture" by one of the authors.

The determination of the amounts of other gases in crude or purified acetylene is for the most part carried out by the methods in vogue for the analysis of coal-gas and other illuminating gases, or by slight modifications of them. For an account of these methods the textbook on "Gas Manufacture" by one of the authors may be consulted. For instance, two of the three principal impurities in acetylene, viz., ammonia and sulphuretted hydrogen, may be detected and estimated in that gas in the same manner as in coal gas. The detection and estimation of phosphine are, however, analytical operations peculiar to acetylene among common illuminating gases, and they must therefore be referred to.

_Table to facilitate the Correction of the Volume of Gas at different Temperatures and under different Atmospheric Pressures._

_____________________________________________________ | | | | | THERMOMETER. | | BAR.|_______________________________________________| | | | | | | | | | | 46° | 48° | 50° | 52° | 54° | 56° | |_____|_______|_______|_______|_______|_______|_______| | | | | | | | | |28.4 | 0.979 | 0.974 | 0.970 | 0.965 | 0.960 | 0.955 | |28.5 | 0.983 | 0.978 | 0.973 | 0.968 | 0.964 | 0.959 | |28.6 | 0.986 | 0.981 | 0.977 | 0.972 | 0.967 | 0.962 | |28.7 | 0.990 | 0.985 | 0.980 | 0.975 | 0.970 | 0.966 | |28.8 | 0.993 | 0.988 | 0.984 | 0.979 | 0.974 | 0.969 | |28.9 | 0.997 | 0.992 | 0.987 | 0.982 | 0.977 | 0.973 | |29.0 | 1.000 | 0.995 | 0.990 | 0.986 | 0.981 | 0.976 | |29.1 | 1.004 | 0.999 | 0.994 | 0.989 | 0.984 | 0.979 | |29.2 | 1.007 | 1.002 | 0.997 | 0.992 | 0.988 | 0.982 | |29.3 | 1.011 | 1.005 | 1.001 | 0.996 | 0.991 | 0.986 | |29.4 | 1.014 | 1.009 | 1.004 | 0.999 | 0.995 | 0.990 | |29.5 | 1.018 | 1.013 | 1.008 | 1.003 | 0.998 | 0.993 | |29.6 | 1.021 | 1.016 | 1.011 | 1.006 | 1.001 | 0.996 | |29.7 | 1.025 | 1.019 | 1.015 | 1.010 | 1.005 | 1.000 | |29.8 | 1.028 | 1.023 | 1.018 | 1.013 | 1.008 | 1.003 | |29.9 | 1.031 | 1.026 | 1.022 | 1.017 | 1.012 | 1.007 | |30.0 | 1.035 | 1.030 | 1.025 | 1.020 | 1.015 | 1.010 | |30.1 | 1.038 | 1.033 | 1.029 | 1.024 | 1.019 | 1.014 | |30.2 | 1.042 | 1.037 | 1.032 | 1.027 | 1.022 | 1.017 | |30.3 | 1.045 | 1.040 | 1.036 | 1.030 | 1.025 | 1.020 | |30.4 | 1.049 | 1.044 | 1.039 | 1.034 | 1.029 | 1.024 | |30.5 | 1.052 | 1.047 | 1.042 | 1.037 | 1.032 | 1.027 | |_____|_______|_______|_______|_______|_______|_______| _____________________________________________________ | | | | | THERMOMETER. | | BAR.|_______________________________________________| | | | | | | | | | | 58° | 60° | 62° | 64° | 66° | 68° | |_____|_______|_______|_______|_______|_______|_______| | | | | | | | | |28.5 | 0.954 | 0.949 | 0.944 | 0.939 | 0.934 | 0.929 | |28.6 | 0.958 | 0.953 | 0.947 | 0.943 | 0.938 | 0.932 | |28.7 | 0.961 | 0.956 | 0.951 | 0.946 | 0.941 | 0.936 | |28.8 | 0.964 | 0.959 | 0.954 | 0.949 | 0.944 | 0.939 | |28.9 | 0.968 | 0.963 | 0.958 | 0.953 | 0.948 | 0.942 | |29.0 | 0.971 | 0.966 | 0.961 | 0.956 | 0.951 | 0.946 | |29.1 | 0.975 | 0.969 | 0.964 | 0.959 | 0.954 | 0.949 | |29.2 | 0.978 | 0.973 | 0.968 | 0.963 | 0.958 | 0.952 | |29.3 | 0.981 | 0.976 | 0.971 | 0.966 | 0.961 | 0.956 | |29.4 | 0.985 | 0.980 | 0.975 | 0.969 | 0.964 | 0.959 | |29.5 | 0.988 | 0.983 | 0.978 | 0.973 | 0.968 | 0.962 | |29.6 | 0.992 | 0.986 | 0.981 | 0.976 | 0.971 | 0.966 | |29.7 | 0.995 | 0.990 | 0.985 | 0.980 | 0.974 | 0.969 | |29.8 | 0.998 | 0.993 | 0.988 | 0.983 | 0.978 | 0.972 | |29.9 | 1.002 | 0.997 | 0.991 | 0.986 | 0.981 | 0.976 | |30.0 | 1.005 | 1.000 | 0.995 | 0.990 | 0.985 | 0.979 | |30.1 | 1.009 | 1.003 | 0.998 | 0.993 | 0.988 | 0.983 | |30.2 | 1.012 | 1.007 | 1.002 | 0.996 | 0.991 | 0.986 | |30.3 | 1.015 | 1.010 | 1.005 | 1.000 | 0.995 | 0.989 | |30.4 | 1.019 | 1.014 | 1.008 | 1.003 | 0.998 | 0.993 | |30.5 | 1.022 | 1.017 | 1.012 | 1.006 | 1.001 | 0.996 | |_____|_______|_______|_______|_______|_______|_______| _____________________________________________ | | | | | THERMOMETER. | | BAR.|_______________________________________| | | | | | | | | | 70° | 72° | 74° | 76° | 78° | |_____|_______|_______|_______|_______|_______| | | | | | | | |28.4 | 0.921 | 0.915 | 0.910 | 0.905 | 0.900 | |28.5 | 0.924 | 0.919 | 0.914 | 0.908 | 0.903 | |28.6 | 0.927 | 0.922 | 0.917 | 0.912 | 0.906 | |28.7 | 0.931 | 0.925 | 0.920 | 0.915 | 0.909 | |28.8 | 0.934 | 0.929 | 0.924 | 0.918 | 0.913 | |28.9 | 0.937 | 0.932 | 0.927 | 0.921 | 0.916 | |29.0 | 0.941 | 0.935 | 0.930 | 0.925 | 0.919 | |29.1 | 0.944 | 0.939 | 0.933 | 0.928 | 0.923 | |29.2 | 0.947 | 0.942 | 0.937 | 0.931 | 0.926 | |29.3 | 0.950 | 0.945 | 0.940 | 0.935 | 0.929 | |29.4 | 0.954 | 0.949 | 0.943 | 0.938 | 0.932 | |29.5 | 0.957 | 0.952 | 0.947 | 0.941 | 0.936 | |29.6 | 0.960 | 0.955 | 0.950 | 0.944 | 0.939 | |29.7 | 0.964 | 0.959 | 0.953 | 0.948 | 0.942 | |29.8 | 0.967 | 0.962 | 0.957 | 0.951 | 0.946 | |29.9 | 0.970 | 0.965 | 0.960 | 0.954 | 0.949 | |30.0 | 0.974 | 0.968 | 0.963 | 0.958 | 0.952 | |30.1 | 0.977 | 0.972 | 0.966 | 0.961 | 0.955 | |30.2 | 0.980 | 0.975 | 0.970 | 0.964 | 0.959 | |30.3 | 0.984 | 0.978 | 0.973 | 0.968 | 0.962 | |30.4 | 0.987 | 0.982 | 0.976 | 0.971 | 0.965 | |30.5 | 0.990 | 0.985 | 0.980 | 0.974 | 0.969 | |_____|_______|_______|_______|_______|_______|

For the detection of phosphine, Bergé's solution may be used. It is a "solution of 8 to 10 parts of corrosive sublimate in 80 parts of water and 20 parts of 30 per cent. hydrochloric acid." It becomes cloudy when gas containing phosphine is passed into it. It is, however, applied most conveniently in the form of Keppeler's test-papers, which have been described in Chapter V. Test-papers for phosphine, the active body in which has not yet been divulged, have recently been produced for sale by F. B. Gatehouse.

The estimation of phosphine will usually require to be carried out either (1) on gas directly evolved from carbide in order to ascertain if the carbide in question yields an excessive proportion of phosphine, or (2) upon acetylene which is presumably purified, drawn either from the outlet of the purifier or from the service-pipes, with the object of ascertaining whether an adequate purification in regard to phosphine has been accomplished. In either case, the method of estimation is the same, but in the first, acetylene should be specially generated from a small representative sample of the carbide and led directly into the apparatus for the absorption of the phosphine. If the acetylene passes into the ordinary gasholder, the amount of phosphine in gas drawn off from the holder will vary from time to time according to the temperature and the degree of saturation of the water in the holder-tank with phosphine, as well as according to the amount of phosphine in the gas generated at the time.

A method frequently employed for the determination of phosphine in acetylene is one devised by Lunge and Cedercreutz. If the acetylene is to be evolved from a sample of carbide in order to ascertain how much phosphine the latter yields to the gas, about 50 to 70 grammes of the carbide, of the size of peas, are brought into a half-litre flask, and a tap-funnel, with the mouth of its stem contracted, is passed through a rubber plug fitting the mouth of the flask. A glass tube passing through the plug serves to convey the gas evolved to an absorption apparatus, which is charged with about 75 c.c. of a 2 to 3 per cent. solution of sodium hypochlorite. The absorption apparatus may be a ten-bulbed absorption tube or any convenient form of absorption bulbs which subject the gas to intimate contact with the solution. If acetylene from a service-pipe is to be tested, it is led direct from the nozzle of a gas- tap to the absorption tube, the outlet of which is connected with an aspirator or the inlet of an experimental meter, by which the volume of gas passed through the solution is measured. But if the generating flask is employed, water is allowed to drop from the tap-funnel on to the carbide in the flask at the rate of 6 to 7 drops a minute (the tap-funnel being filled up from time to time), and all the carbide will thus be decomposed in 3 to 4 hours. The flask is then filled to the neck with water, and disconnected from the absorption apparatus, through which a little air is then drawn. The absorbing liquid is then poured, and washed out, into a beaker; hydrochloric acid is added to it, and it is boiled in order to expel the liberated chlorine. It is then usual to precipitate the sulphuric acid by adding solution of barium chloride to the boiling liquid, allowing it to cool and settle, and then filtering. The weight of barium sulphate obtained by ignition of the filter and its contents, multiplied by 0.137, gives the amount of sulphur present in the acetylene in the form of sulphuretted hydrogen. The filtrate and washings from this precipitate are rendered slightly ammoniacal, and a small excess of "magnesia mixture" is added; the whole is stirred, left to stand for 12 hours, filtered, the precipitate washed with water rendered slightly ammoniacal, dried, ignited, and weighed. The weight so found multiplied by 0.278 gives the weight of phosphorus in the form of phosphine in the volume of gas passed through the absorbent liquid.

Objection may rightly be raised to the Lunge and Cedercreutz method of estimating the phosphine in crude acetylene on the ground that explosions are apt to occur when the gas is being passed into the hypochlorite solution. Also it must be borne in mind that it aims at estimating only the phosphorus which is contained in the gas in the form of phosphine, and that there may also be present in the gas organic compounds of phosphorus which are not decomposed by the hypochlorite. But when the acetylene is evolved from the carbide in proper conditions for the avoidance of appreciable heating it appears fairly well established that phosphorus compounds other than phosphine exist in the gas only in practically negligible amount, unless the carbide decomposed is of an abnormal character. Various methods of burning the acetylene and estimating the phosphorus in the products of combustion have, however been proposed for the purpose of determining the total amount of phosphorus in acetylene. Some of them are applicable to the simultaneous determination of the total sulphur in the acetylene, and in this respect become akin to the Gas Referees' method for the determination of the sulphur compounds in coal-gas.

Eitner and Keppeler have proposed to burn the acetylene on which the estimation is to be made in a current of neat oxygen. But this procedure is rather inconvenient, and by no means essential. Lidholm liberated acetylene slowly from 10 grammes of carbide by immersing the carbide in absolute alcohol and gradually adding water, while the gas mixed with a stream of hydrogen leading to a burner within a flask. The flow of hydrogen was reduced or cut off entirely while the acetylene was coming off freely, but hydrogen was kept burning for ten minutes after the flame had ceased to be luminous in order to ensure the burning of the last traces of acetylene. The products of combustion were aspirated through a condenser and a washing bottle, which at the close were rinsed out with warm solution of ammonia. The whole of the liquid so obtained was concentrated by evaporation, filtered in order to remove particles of soot or other extraneous matter, and acidified with nitric acid. The phosphoric acid was then precipitated by addition of ammonium molybdate.

J. W. Gatehouse burns the acetylene in an ordinary acetylene burner of from 10 to 30 litres per hour capacity, and passes the products of combustion through a spiral condensing tube through which water is dropped at the rate of about 75 c.c. per hour, and collected in a beaker. The burner is placed in a glass bell-shaped combustion chamber connected at the top through a right-angled tube with the condenser, and closed below by a metal base through which the burner is passed. The amount of gas burnt for one determination is from 50 to 100 litres. When the gas is extinguished, the volume consumed is noted, and after cooling, the combustion chamber and condenser are washed out with the liquid collected in the beaker and finally with distilled water, and the whole, amounting to about 400 c.c., is neutralised with solution of caustic alkali (if decinormal alkali is used, the total acidity of the liquid thus ascertained may be taken as a convenient expression of the aggregate amount of the sulphuric, phosphoric and silicic acids resulting from the combustion of the total corresponding impurities in the gas), acidified with hydrochloric acid, and evaporated to dryness with the addition towards the end of a few drops of nitric acid. The residue is taken up in dilute hydrochloric acid; and silica filtered off and estimated if desired. To the filtrate, ammonia and magnesia mixture are added, and the magnesium pyrophosphate separated and weighed with the usual precautions. Sulphuric acid may, if desired, be estimated in the filtrate, but in that case care must be taken that the magnesia mixture used was free from it.

Mauricheau-Beaupré has elaborated a volumetric method for the estimation of the phosphine in crude acetylene depending on its decomposition by a known volume of excess of centinormal solution of iodine, addition of excess of standard solution of sodium thiosulphate, and titrating back with decinormal solution of iodine with a few drops of starch solution as an indicator. One c.c. of centinormal solution of iodine is equivalent to 0.0035 c.c. of phosphine. This method of estimation is quickly carried out and is sufficiently accurate for most technical purposes.

In carrying out these analytical operations many precautions have to be taken with which the competent analyst is familiar, and they cannot be given in detail in this work, which is primarily intended for ordinary users of acetylene, and not for the guidance of analysts. It may, however, be pointed out that many useful tests in connexion with acetylene supply can be conducted by a trained analyst, which are not of a character to be serviceable to the untrained experimentalist. Among such may be named the detection of traces of phosphine in acetylene which has passed through a purifier with a view to ascertaining if the purifying material is exhausted, and the estimation of the amount of air or other diluents in stored acetylene or acetylene generated in a particular manner. Advice on these points should be sought from competent analysts, who will already have the requisite information for the carrying out of any such tests, or know where it is to be found. The analyses in question are not such as can be undertaken by untrained persons. The text-book on "Gas Manufacture" by one of the authors gives much information on the operations of gas analysis, and may be consulted, along with Hempel's "Gas Analysis" and Winkler and Lunge's "Technical Gas Analysis."

APPENDIX

DESCRIPTIONS OF A NUMBER OF ACETYLENE GENERATORS AS MADE IN THE YEAR 1909

(_The purpose of this Appendix is explained in Chapter IV., page 111, and a special index to it follows the general index at the end of this book._)

AMERICA--CANADA.

_Maker_: SICHE GAS CO., LTD., GEORGETOWN, ONTARIO.

_Type_: Automatic; carbide-to-water.

The "Siche" generator made by this firm consists of a water-tank _A_, having at the bottom a sludge agitator _N_ and draw-off faucet _O_, and rigidly secured within it a bell-shaped generating chamber _B_, above which rises a barrel containing the feed chamber _C_, surmounted by the carbide chamber _D_. The carbide used is granulated or of uniform size. In the generating chamber _B_ is an annular float _E_, nearly filling the area of the chamber, and connected, by two rods passing, with some lateral play, through apertures in the conical bottom of the feed chamber _C_, to the T-shaped tubular valve _F_. Consequently when the float shifts vertically or laterally the rods and valves at once move with it. The angle of the cone of the feed chamber and the curve of the tubular valve are based on the angle of rest of the size of carbide used, with the object of securing sensitiveness of the feed. The feed is thus operated by a very small movement of the float, and consequently there is but very slight rise and fall of the water in the generating chamber. Owing to the lateral play, the feed valve rarely becomes concentric with its seat. There is a cover _G_ over the feed valve _F_, designed to distribute the carbide evenly about the feed aperture and to prevent it passing down the hollow of the valve and the holes through which the connecting-rods pass. It also directs the course of the evolved gas on its way to the service-pipe through the carbide in the feed chamber _C_, whereby the gas is dried. The carbide chamber _D_ has at its bottom a conical valve, normally open, but closed by means of the spindle _H_, which is engaged at its upper end by the closing screw-cap _J_, which is furnished with a safelocking device to prevent its removal until the conical valve is closed and the hopper chamber _D_ thereby cut off from the gas-supply. The cap _J_, in addition to a leather washer to make a gas-tight joint when down, has a lower part fitting to make an almost gas-tight joint. Thus when the cap is off; the conical valve fits gas-tight; when it is on and screwed down it is gas-tight; and when on but not screwed down, it is almost gas-tight. Escape of gas is thus avoided. A special charging funnel _K_, shown in half-scale, is provided for inserting in place of the screw cap. The carbide falls from the funnel into the chamber _D_ when the chain is pulled. A fresh charge of carbide may be put in while the apparatus is in action. The evolved gas goes into the chamber _C_ through a pipe, with cock, to a dust-arrester _L_, which contains a knitted stocking lightly filled with raw sheep's wool through which the gas passes to the service- pipe. The dust-arrester needs its contents renewing once in one, two, or three years, according to the make of gas. The pressure of the gas is varied as desired by altering the height of water in the tank _A_. When cleaning the machine, the water must never be run below the top of the generating chamber.

AMERICA--UNITED STATES.

_Maker:_ J. B. COLT CO., 21 BARCLAY STREET, NEW YORK.

_Type:_ Automatic; carbide-to-water.

The "Colt" generator made by this firm comprises a carbide hopper mounted above a generating tank containing water, and an equalising bell gasholder mounted above a seal-pot having a vent-pipe _C_ communicating with the outer air. The carbide hopper is charged with 1/4 x 1/12 inch carbide, which is delivered from it into the water in the generating tank in small portions at a time through a double valve, which is actuated through levers connected to the crown of the equalising gasholder. As the bell of the gasholder falls the lever rotates a rock shaft, which enters the carbide hopper, and through a rigidly attached lever raises the inner plunger of the feed-valve. The inner plunger in turn raises the concentric outer stopper, thereby leaving an annular space at the base of the carbide hopper, through which a small delivery of carbide to the water in the generating tank then ensues. The gas evolved follows the course shown by the arrows in the figure into the gasholder, and raises the bell, thereby reversing the action of the levers and allowing the valve to fall of its own weight and so cut off the delivery of carbide. The outer stopper of the valve descends before the inner plunger and so leaves the conical delivery mouth of the hopper free from carbide. The inner plunger, which is capped at its lower end with rubber, then falls and seats itself moisture-tight on the clear delivery mouth of the hopper. The weight of the carbide in the hopper is taken by its sides and a projecting flange of the valve casing, so that the pressure of the carbide at the delivery point is slight and uniform. The outside of the delivery mouth is finished by a drip collar with double lip to prevent condensed moisture creeping upwards to the carbide in the hopper. A float in the generating tank, by its descent when the water falls below a certain level, automatically draws a cut off across the delivery mouth of the carbide hopper and so prevents the delivery of carbide either automatically or by hand until the water in the generating tank has been restored to its proper level. Interlocking levers, (11) and (12) in the figure, prevent the opening of the feed valve while the cap (10) of the carbide hopper is open for recharging the hopper. There is a stirrer actuated by a handle (9) for preventing the sludge choking the sludge cock. The gas passes into the gasholder through a floating seal, which serves the dual purpose of washing it in the water of the gasholder tank and of preventing the return of gas from the holder to the generating tank. From the gasholder the gas passes to the filter (6) where it traverses a strainer of closely woven cotton felt for the purpose of the removal of any lime.

Drip pipes (30) and (31) connected to the inlet- and outlet-pipes of the gasholder are sealed in water to a depth of 6 inches, so that in the event of the pressure in the generator or gasholder rising above that limit the surplus gas blows through the seal and escapes through the vent-pipe _C_. There is also a telescopic blow-off (32) and (33), which automatically comes into play if the gasholder bell rises above a certain height.

_Maker:_ DAVIS ACETYLENE CO., ELKHARDT, INDIANA.

_Type:_ Automatic; carbide-to-water.

The "Davis" generator made by this firm comprises an equalising bell gasholder with double walls, the inner wall surrounding a central tube rising from the top of the generating chamber, in which is placed a water-sealed carbide chamber with a rotatory feeding mechanism which is driven by a weight motor. The carbide falls from the chamber on to a wide disc from which it is pushed off a lump at a time by a swinging displacer, so arranged that it will yield in every direction and prevent clogging of the feeding mechanism. Carbide falls from the disk into the water of the generating chamber, and the evolved gas raises the bell and so allows a weighted lever to interrupt the action of the clockwork, until the bell again descends. The gas passes through a washer in the gasholder tank, and then through an outside scrubber to the service-pipe. There is an outside chamber connected by a pipe with the generating chamber, which automatically prevents over-filling with water, and also acts as a drainage chamber for the service- and blow-off-pipes. There is an agitator for the residuum and a sludge-cock through which to remove same. The feeding mechanism permits the discharge of lump carbide, and the weight motor affords independent power for feeding the carbide, at the same time indicating the amount of unconsumed carbide and securing uniform gas pressure.

_Maker:_ SUNLIGHT GAS MACHINE CO., 49 WARREN STREET, NEW YORK.

_Type:_ Automatic; carbide-to-water.

The "Omega" apparatus made by this firm consists of a generating tank containing water, and surmounted by a hopper which is filled with carbide of 1/4-inch size. The carbide is fed from the hopper into the generating tank through a mechanism consisting of a double oscillating cup so weighted that normally the feed is closed. The fall of the bell of the equalising gasholder, into which the gas evolved passes, operates a lever _B_, which rotates the weighted cup in the neck of the hopper and so causes a portion of carbide to fall into the water in the generating tank. The feed-cup consists of an upper cup into which the carbide is first delivered. It is then tipped from the upper cup into the lower cup while, at the same time, further delivery from the hopper is prevented. Thus only the portion of carbide which has been delivered into the lower cup is emptied at one discharge into the generator. There is a safety lock to the hopper cap which prevents the feeding mechanism coming into operation until the hopper cap is screwed down tightly. Provision is made for a limited hand-feed of carbide to start the apparatus. The gasholder is fitted with a telescoping vent-pipe, by which gas escapes to the open in the event of the bell being raised above a certain height. There is also an automatic cut-off of the carbide feed, which comes into operation it the gas is withdrawn too rapidly whether through leakage in the pipes or generating plant, or through the consumption being increased above the normal generating capacity of the apparatus. The gas evolved passes into a condensing or washing chamber placed beneath the gasholder tank and thence it travels to the gasholder. From the gasholder it goes through a purifier containing "chemically treated coke and cotton" to the supply-pipe.

1 Vent-cock handle. 2 Residuum-cock handle. 3 Agitator handle. 4 Filling funnel. 5 Water overflow. 6 Hopper cap and lever. 7 Starting feed. 8 Rocker arm. 9 Feed connecting-rod. A Pawl. B Lever for working feed mechanism. C Guide frame. D Residuum draw-off cock. G Chain from hopper cap to feed mechanism. H Blow-off and vent-pipe connexion. I Gas outlet from generator. J Gas service-cock. K Filling funnel for gasholder tank. L Funnel for condensing chamber. M Gas outlet at top of purifier. N Guides on gas-bell. O Crosshead on swinging pawl. P Crane carrying pawl. Q Shaft connecting feed mechanism. R Plug in gas outlet-pipe. S Guide-frame supports. U Removable plate to clean purifier. Z Removable plate to expose feed-cups for cleaning same.

AUSTRIA-HUNGARY

_Maker:_ RICH. KLINGER, GUMPOLDSKIRCHEN, NEAR VIENNA.

_Type:_ Non-automatic; carbide-to-water.

The generating plant made by this firm consists of the generator _A_ which is supported in a concrete water and sludge tank _B_, a storage gasholder _J_, and purifiers _K_. In the top of the generator are guide-ways _F_, through each of which is passed a plunger _C_ containing a perforated cage charged with about 8 lb. of lump carbide. The plungers are supported by ropes passing over pulleys _D_, and when charged they are lowered through the guide-ways _F_ into the water in the tank _B_. The charge of carbide is thus plunged at once into the large body of water in the tank, and the gas evolved passes through perforations in the washer _G_ to the condenser _H_ and thence to the storage gasholder _J_. After exhaustion of the charge the plungers are withdrawn and a freshly charged cage of carbide inserted ready for lowering into the generating tank. There is a relief seal _f_ through which gas will blow and escape by a pipe _g_ to the open should the pressure within the apparatus exceed the depth of the seal, viz., about 9 inches. There is a syphon pot _N_ for the collection and withdrawal of condensed water. The sludge is allowed to accumulate in the bottom of the concrete tank _B_ until it becomes necessary to remove it at intervals of about three months. Water is added to the tank daily to replace that used up in the generation of the gas. The gas passes from the storage holder through one of the pair of purifiers _K_, with water-sealed lids, which are charged with a chemical preparation for the removal of phosphoretted hydrogen. This purifying material also acts as a desiccating agent. From the purifiers the gas passes through the meter _L_ to the service- pipes.

BELGIUM.

_Maker_: SOC. AN. DE L'ACÉTYLITHE, 65 RUE DU MARCHE, BRUSSELS.

_Type_: Automatic; contact.

The generating apparatus made by this firm uses, instead of ordinary carbide, a preparation known as "acétylithe," which is carbide treated specially with mineral oil, glucose and sugar. The object of using this treated carbide is to avoid the effects of the attack of atmospheric humidity or water vapour, which, with ordinary carbide, give rise to the phenomena of after-generation. The generator comprises a water-tank _A_ with conical base, a basket _C_ containing the treated carbide inserted within a cylindrical case _B_ which is open at the bottom and is surmounted by a cylindrical filter _D_. At starting, the tank _A_ is filled with water to the level _N N'_. The water rises within the cylindrical case until it comes in contact with the treated carbide, which thereupon begins to evolve gas. The gas passes through the filter _D_, which is packed with dry cotton-wool, and escapes through the tap _M_. As soon as the contained air has been displaced by gas the outlet of the tap _M_ is connected by a flexible tube to the pipe leading to a purifier and the service-pipe. When the tap _M_ is closed, or when the rate of evolution of the gas exceeds the rate of consumption, the evolved gas accumulates within the cylindrical case _B_ and begins to displace the water, the level of which within the case is lowered from _S S'_, first to _S1 S'1_ and ultimately to, say, _S2 S'2_. The evolution of gas is thereby gradually curtailed or stopped until more is required for consumption. The water displacement causes the water-level in the outer tank to rise to _N1 N'1_ and ultimately to, say _N2 N'2_. The lime formed by the decomposition of the carbide is loosened from the unattacked portion and taken more or less into solution as sucrate of lime, which is a soluble salt which the glucose or sugar in the treated carbide forms with lime. The solution is eventually run off through the cock _R_. The cover _T_ of the filter is screwed down on rubber packing until gas- tight. The purifier is charged with puratylene or other purifying material.

_Maker_: L. DEBRUYNE, 22 PLACE MASUI, BRUSSELS.

_Type_: (1) Automatic; carbide-to-water.

The generating plant made by this firm, using granulated carbide, comprises an equalising gasholder _E_ alongside a generating tank _B_, which is surmounted by a closed carbide receptacle _A_ and a distributing appliance. The carbide receptacle is filled with granulated carbide and the lid _N_ screwed down; the carbide is then withdrawn from the base of the receptacle by the distributing appliance and discharged in measured quantities as required into the water in the generating tank. The distributing appliance is actuated by a weighted cord _H_ attached to the bell _I_ of the gasholder and discharges at each time a quantity of carbide only sufficient nearly to fill the gasholder with acetylene. The gas passes from the generator through the pipe _J_ and seal-pot _D_, or bypass _F_, to the gasholder. The generating tank is provided with a funnel _G_ for replacing the water consumed, a sludge-stirrer and a draw-off cock _L_, and a water-level cock _C_. The gas passes from the gasholder through a purifier _K_, charged with heratol, to the service-pipe.

(2) Automatic; carbide-to-water.

The "Debruyne" generator comprises an equalising bell gasholder _A_ placed alongside a generating tank _B_ containing water into which lump carbide is discharged as necessary from each in turn of a series of chambers mounted in a ring above the generating tank. The chambers are removable for refilling, and when charged are hermetically sealed until opened in turn above the shoot _C_, through which their contents are discharged into the generating tank. The carbide contained in each chamber yields sufficient gas nearly to fill the gasholder. The discharging mechanism is operated through an arm _E_ attached to the bell _G_ of the gasholder, which sets the mechanism in motion when the bell has fallen nearly to its lowest position. The lip _L_ serves for renewing the water in the generator, and the gas evolved goes through the pipe _K_ with tap _F_ to the gasholder. There is an eccentric stirrer for the sludge and a large-bore cock for discharging it. The gas passes from the gasholder through the pipe _J_ to the purifier _H_, charged with heratol, and thence to the service-pipe.

_Maker_: DE SMET VAN OVERBERGE, ALOST.

_Type_: (1) Automatic; carbide-to-water.

This generating apparatus comprises an equalising gasholder _A_ placed alongside a generating tank _B_, above which is mounted on a rotating spindle a series of chambers _C_, arranged in a circle, which are filled with carbide. The generating tank is closed at the top, but on one side there is a shoot _D_ through which the carbide is discharged from the chambers in turn into the water in the tank. The series of chambers are rotated by means of a cord passing round a pulley _E_ and having a weight _F_ at one end, and being attached to the bell of the gasholder at the other. When the bell falls, owing to the consumption of gas, to a certain low position, the carbide chamber, which has been brought by the rotation of the pulley over the shoot, is opened at the bottom by the automatic liberation of a catch, and its contents are discharged into the generating tank. The contents of one carbide chamber suffice to fill the gasholder to two-thirds of its total capacity. The carbide chambers after filling remain hermetically closed until the bottom is opened for the discharge of the carbide. There is a sludge-cock _G_ at the bottom of the generating tank. The gas passes from the gasholder through a purifier _H_, which is ordinarily charged with puratylene.

(2) Non-automatic; carbide-to-water.

This apparatus comprises a storage bell gasholder _J_ placed alongside a generating tank in the top of which is a funnel _E_ with a counter-weighted lever pivoted on the arm _B_. The base of the funnel is closed by a flap valve _C_ hinged at _D_. When it is desired to generate gas the counter-weight _A_ of the lever is raised and the valve at the bottom of the funnel is thereby opened. A charge of carbide is then tipped into the funnel and drops into the water in the generating tank. The valve is then closed and the gas evolved goes through the pipe _G_ to the gasholder, whence it passes through a purifier to the service-pipe. There is a sludge-cock on the generating tank.

_Maker_: SOC. AN. BELGE DE LA PHOTOLITHE, 2 RUE DE HUY, LIÉGE.

_Type_: Automatic; carbide-to-water.

The "Photolithe" generating plant made by this firm comprises an equalising bell gasholder _A_ in the tank _O_, alongside a generating tank _B_ which is surmounted by a carbide storage receptacle divided into a number of compartments. These compartments are fitted with flap bottoms secured by catches, and are charged with carbide. Through the middle of the storage receptacle passes a spindle, to the upper end of which is attached a pulley _b_. Round the pulley passes a chain, one end of which carries a weight _n_, while in the other direction it traverses guide pulleys and is attached to a loop on the crown of the gasholder bell. When the bell falls below a certain point owing to the consumption of gas, it pulls the chain and rotates the pulley _b_ and therewith an arm _d_, which liberates the catch supporting the flap-bottom of the next in order of the carbide compartments. The contents of this compartment are thereby discharged through the shoot _C_ into the generating tank _B_. The gas evolved passes through the cock _R_ and the pipe _T_ into the gasholder, the rise of the bell of which takes the pull off the chain and allows the weight at its other end to draw it up until it is arrested by the stop _f_. The arm _d_ is thereby brought into position to liberate the catch of the next carbide receptacle. The generating tank is enlarged at its base to form a sludge receptacle _E_, which is provided with a sludge draw-off cock _S_ and a hand-hole _P_. Between the generating tank proper and the sludge receptacle is a grid, which is cleaned by means of a rake with handle _L_. The gas passes from the gasholder through a purifier _H_ charged with puratylene, to the service-pipe.

The same firm also makes a portable generating apparatus in which the carbide is placed in a basket in the crown of the bell of the gasholder. This apparatus is supplied on a trolley for use in autogenous soldering or welding.

FRANCE.

_Maker_: LA SOC. DES APPLICATIONS DE L'ACÉTYLÈNE, 26 RUE CADET, PARIS.

_Type_: Automatic; carbide-to-water.

The "Javal" generating plant made by this firm consists of an equalising bell gasholder _A_ in the tank _B_ with a series of buckets _D_, with removable bottoms _h_, mounted on a frame _F_ round the guide framing of the holder. Alongside the gasholder stands the generating tank _H_ with shoot _K_, into which the carbide discharged from the buckets falls. On top of the generator is a tipping water-bucket _I_ supplied with water through a ball cock. The bell of the gasholder is connected by chains _a_ and _c_, and levers _b_ and _d_ with an arm which, when the bell descends to a certain point, comes in contact with the catch by which the bottom of the carbide bucket is held in place, and, liberating the same, allows the carbide to fall into the shoot. When the bell rises, in consequence of the evolved gas, the ring of carbide buckets is rotated sufficiently to bring the next bucket over the shoot. Thus the buckets are discharged in turn as required through the rise and fall of the gasholder bell.

The carbide falling from the opened bucket strikes the end _i_ of the lever _k_, and thereby tips the water-bucket _I_ and discharges its contents into the shoot of the generator. The rise in the level of the water in the generator, due to the discharge of the water from the bucket _I_, lifts the float _L_ and therewith, through the attached rod and chain _u_, the ball _s_ of the valve _t_. The sludge, which has accumulated in the base _N_ of the generator from the decomposition of the previous portion of carbide, is thereby discharged automatically into a special drain. The discharge- valve closes automatically when the float _L_ has sunk to its original level. The gas evolved passes from the generator through the seal-pot _M_ and the pipe _r_ with cock _q_ into the gasholder, from which it passes through the pipe _x_; with condensation chamber and discharge tap _y_ into the purifier _R_, which is charged with heratol.

_Maker_: L'HERMITE, LOUVIERS, EURE.

_Type_: (1) Automatic; carbide-to-water.

The generating plant known as "L'Éclair," by this firm comprises an equalising bell gasholder _A_ floating in an annular water-seal _N_, formed in the upper part of a generating tank _B_ into which carbide enters through the shoot _K_. Mounted at the side of the tank is the carbide delivery device, which consists of the carbide containers _J_ supported on an axis beneath the water-sealed cover _H_. The containers are filled with ordinary lump carbide when the cover _H_ is removed. The tappet _O_ attached to the bell of the gasholder come in contact with a pawl when the gasholder bell descends to a certain level and thereby rotates a pinion on the protruding end of the axis which carries the carbide containers _J_. Each time the bell falls and the tappet strikes the pawl, one compartment of the carbide containers discharges its contents down the shoot _K_ into the generating tank _B_. The gas evolved passes upwards and causes the bell _A_ to rise. The gas is prevented from rising into the shoot by the deflecting plates _G_. The natural level of the water in the generating tank, when the apparatus is in use, is shown by the dotted lines _L_. The lime sludge is discharged from time to time through the cock _E_, being stirred up by means of the agitator _C_ with handle _D_. When the sludge is discharged water is added through _M_ to the proper level. The gas evolved passes from the holder through the pipe with tap _F_ to the service-pipe. A purifier is supplied if desired.

_References_

A Gasholder. B Generator. C Agitator. D Handle of agitator. E Sludge-cock. F Gas outlet. G Deflecting plates. H Cover. I Carbide. J Automatic distributor. K Shoot. L Water-level. M Water-inlet. N Water-seal. O Tappet.

(2) Automatic; water-to-carbide; contact.

A generating plant known as "L'Étoile" made by this firm. A tappet on the bell of an equalising gasholder depresses a lever which causes water to flow into a funnel, the outlet of which leads to a generating chamber containing carbide.

_Maker_: MAISON SIRIUS, FR. MANGIAMELI & CO., 34 RUE DES PETITS- HÔTELS, PARIS.

_Type_: (1) Automatic; carbide-to-water.

The generating plant made by this firm comprises a drum-shaped carbide holder mounted above a generating tank, a condenser, a washer, an equalising gasholder, and a purifier. The drum _A_ is divided into eight chambers _a_ each closed by a fastening on the periphery of the drum. These chambers are packed with lump carbide, which is discharged from them in turn through the funnel _B_ into the generating tank, which is filled with water to the level of the overflow cock _b_. A deflecting plate _d_ in the tank distributes the carbide and prevents the evolved gas passing out by way of the funnel _B_. The gas evolved passes through the pipe _O_ into the condenser, which is packed with coke, through which the gas goes to the pipe _E_ and so to the washer _P_ through the water, in which it bubbles and issues by the pipe _G_ into the gasholder. The bell _L_ of the gasholder is connected by a chain _C_ to the axis of the drum _A_, on which is a pinion with pawl so arranged that the pull on the chain caused by the fall of the bell of the gasholder rotates the drum by 1/8 of a turn. The catch on the outside of the carbide chamber, which has thereby been brought to the lowest position, is at the same time freed, so that the contents of the chamber are discharged through the funnel _B_. The evolved gas causes the bell to rise and the drum remains at rest until, owing to the consumption of gas, the bell again falls and rotates the drum by another 1/8 of a turn. Each chamber of the drum holds sufficient carbide to make a volume of gas nearly equal to the capacity of the gasholder. Thus each discharge of carbide very nearly fills the gasholder, but cannot over-fill it. The bell is provided with a vent-pipe _i_, which comes into operation should the bell rise so high that it is on the point of becoming unsealed. From the gasholder the gas passes through the pipe _J_, with cock _e_, to the purifier, which is charged with frankoline, puratylene, or other purifying material, whence it passes to the pipe _N_ leading to the place of combustion. The generating tank is provided with a sludge-cock _g_, and a cleaning opening with lid _f_. This generating plant has been primarily designed for the use of acetylene for autogenous welding, and is made also mounted on a suitable trolley for transport for this purpose.

(2) Automatic; carbide-to-water.

A later design of generating plant, known as the Type G, also primarily intended for the supply of acetylene for welding, has the carbide store mounted in the crown of the bell of the equalising gasholder, to the framing of the tank of which are attached a purifier, charged with frankoline, and a safety water-seal or valve. The whole plant is mounted on a four-legged stand, and is provided with handles for carrying as a whole without dismounting. It is made in two sizes, for charges of 5-1/2 and 11 lb. of carbide respectively.

GERMANY.

_Maker_: KELLER AND KNAPPICH, G.m.b.H., AUGSBURG.

_Type_: Non-automatic; carbide-to-water.

The "Knappich" generating plant made by this firm embodies a generating tank, one-half of which is closed, and the other half of which is open at the top, containing water. A small drum containing carbide is attached by a clamp to the end of a lever which projects above the open half of the tank. The lever is fastened to a horizontal spindle which is turned through 180° by means of a counter-weighted lever handle. The carbide container is thus carried into the water within the closed half of the tank, and is opened automatically in transit. The carbide is thus exposed to the water and the evolved gas passes through a pipe from the top of the generating tank to a washer acting on the Livesey principle, and thence to a storage gasholder. The use of closed carbide containers in charging is intended to preclude the introduction of air into the generator, and the evolution and escape of gas to the air while the carbide is being introduced. Natural circulation of the water in the generating tank is encouraged with a view to the dissipation of heat and washing of the evolved gas. From the gasholder the gas passes in a downward direction through two purifiers arranged in series, charged with a material supplied under the proprietary name of "Carburylen." This material is stated to act as a desiccating as well as a purifying agent. The general arrangement of the plant is shown in the illustration. (Fig. 38).

_Maker_: NORDISCHE AZETYLEN-INDUSTRIE; ALTONA-OTTENSEN.

_Type_: Automatic; water-to-carbide; "drawer."

The apparatus made by this firm consists of an equalising gasholder with bell _D_ and tank _E_, a water-tank _O_, and two drawer generators _C_ situated in the base of the gasholder tank. The water-supply from the tank _O_ through the pipe _P_ with valve _Q_ is controlled by the rise and fall of the bell through the medium of the weight _J_ attached to the bell. When the bell descends this weight rests on _K_ and so moves a counter-weighted lever, which opens the valve _Q_. The water then flows through the nozzle _B_ into one division of the funnel _A_ and down the corresponding pipe to one of the generators. The generators contain trays with compartments intended to be half filled with carbide. The gas evolved passes up the pipe _T_ and through the seal _U_ into the bell of the gasholder. There is a safety pipe _F_, the upper end of which is carried outside the generator house. From the gasholder the gas is delivered through the cock _M_ to a purifier charged with a special purifying material mixed with cork waste and covered with wadding. There is a drainage cock _N_ at the base of the purifier. The nozzle _B_ of the water-supply pipe is shifted to discharge into either compartment of the funnel _A_, according to which of the two generators is required to be in action. The other generator may then be recharged without interfering with the continuous working of the plant.

GREAT BRITAIN AND IRELAND.

_Maker:_ THE ACETYLENE CORPORATION OF GREAT BRITAIN LTD., 49 VICTORIA STREET, LONDON, S.W.

_Type:_ (1) Automatic; water-to-carbide; contact, superposed pans.

The "A1" generating plant made by this firm comprises a bell gasholder, with central guide, standing alongside the generator. The generator consists of a rectangular tank in which is a generating chamber having a water-sealed lid with pressure test-cock _I_. Into the generating chamber fit a number of pans _J_, which are charged with carbide. Water is supplied to the generating chamber from an overhead tank _B_ through the starting tap _D_ and the funnel _E_. It flows out of the supply-pipe near the top of the generating chamber through a slot in the side of the pipe facing the corner of the chamber, so that it runs down the latter without splashing the carbide in the upper pans. It enters first the lowest carbide pan through the perforations, which are at different levels in the side of the pan. It thus attacks the carbide from the bottom upwards. The evolved gas passes from the generating chamber through a pipe opening near the top of the same to the washer _A_, which forms the base of the generating tank. It bubbles through the water in the washer, which therefore also serves as a water-seal, and passes thence to the gasholder. On the bell of the gasholder is an arm _C_ which, when the holder descends nearly to its lowest point, depresses the rod _C_, which is connected by a chain to a piston in the outlet-pipe from the water-tank _B_. The fall of the gasholder thereby raises the piston and allows water to flow out of the tank _B_ through the tap _D_ to the funnel _E_. The generating tank is connected by a pipe, with tap _G_, with the washer _A_, and the water in the generating tank is run off through this pipe each time the generating chamber is opened for recharging, thereby flushing out the washer _A_ and renewing the water in the same. There is a sludge discharging tap _F_. With a view to the ready dissipation of the heat of generation the generating chamber is made rectangular and is placed in a water-tank as described. Some of the heat of generation is also communicated to the underlying washer and warms the water in it, so that the washing of the gas is effected by warm water. Water condensing in the gasholder inlet-pipe falls downwards to the washer. There is a water lip _H_ by which the level of the water in the washer is automatically kept constant. The gasholder is provided with a safety-pipe _K_, which allows gas to escape through it to the open before the sides of the holder become unsealed, should the holder for any reason become over-filled. The holder is of a capacity to take the whole of the gas evolved from the carbide in one pan, and the water- tank _B_ holds just sufficient water for the decomposition of one charge of the generator. From the gasholder the gas passes through a purifier, which is ordinarily charged with "Klenzal," and a baffle-box for abstraction of dust, to the service-pipe. With plants intended to supply more than forty lights for six hours, two or more generating chambers are employed, placed in separate compartments of one rectangular generating tank. The water delivery from the water-tank _B_ then takes place into a trough with outlets at different levels for each generating chamber. By inspection of this trough it may be seen at once whether the charge in any generating chamber is unattacked, in course of attack, or exhausted.

(2) Automatic; water-to-carbide; contact.

The same firm also makes the "Corporation Flexible-Tube Generator," which is less costly than the "A1" (_vide supra_). The supply of water to the generating vessels takes place from the tank of the equalising bell gasholder and is controlled by a projection on the bell which depresses a flexible tube delivering into the generating vessels below the level of the water inlet to the tube.

(3) Automatic; water-to-carbide; "drawer."

The same firm also makes a generator known as the "A-to-Z," which is less costly than either of the above. In it water is supplied from the tank of a bell gasholder to a drawer type of generator placed in the base of the gasholder tank. The supply of water is controlled by an external piston- valve actuated through the rise and fall of the bell of the gasholder. The flow of water to the generator is visible.

_Maker_: THE ACETYLENE GAS AND CARBIDE OF CALCIUM CO., PONTARDAWE, R.S.O., GLAM.

_Type_: Automatic; water-to-carbide; flooded compartment.

The "Owens" generator made by this firm comprises an equalising bell gasholder alongside which are placed two or more inclined generating cylinders. The front lower end of each cylinder is fitted with a lid which is closed by a screw clamp. There is inserted in each cylinder a cylindrical trough, divided into ten compartments, each of which contains carbide. Water is supplied to the upper ends of the cylinders from a high-level tank placed at the back of the gasholder. In the larger sizes the tank is automatically refilled from a water service through a ball-cock. The outlet-valve of this tank is operated through a counter- weighted lever, the unweighted end of which is depressed by a loop, attached to the crown of the gasholder bell, when the bell has nearly reached its lowest position. This action of the bell on the lever opens the outlet-valve of the tank and allows water to flow thence into one of the generating cylinders. It is discharged into the uppermost of the compartments of the carbide trough, and when the carbide in that compartment is exhausted it flows over the partition into the next compartment, and so on until the whole trough is flooded. The gas passes from the generating cylinders through a water-seal and a baffle plate condenser placed within the water link of the gasholder to the bell of the latter. There is a water seal on the water supply-pipe from the tank to the generators, which would be forced should the pressure within the generators for any reason become excessive. There is also a sealed vent- pipe which allows of the escape of gas from the holder to the open should the holder for any reason be over filled. The gas passes from the holder through a purifier charged with "Owens" purifying material to the service pipe. The plant is shown in Fig 41.

_Maker_ ACETYLENE ILLUMINATING CO, LTD, 268-270 SOUTH LAMBETH ROAD, LONDON, SW

_Type_ (1) Non automatic, carbide to water

The generator _A_ of this type made by this firm is provided with a loading box _B_, with gas tight lid, into which the carbide is put. It is then discharged by moving a lever which tilts the hinged bottom _D_ of the box _B_, and so tips the carbide through the shoot _E_ on to the conical distributor _F_ and into the water in the generating chamber. There is a sludge cock _G_ at the base of the generator. Gas passes as usual from the generator to a washer and storage gasholder. Heratol is the purifying material supplied.

(2) Non-automatic; water-to-carbide; contact.

The generator _A_ is provided with a carbide container with perforated base, and water is supplied to it from a delivery-pipe through a scaled overflow. The gas evolved passes through the pipe _E_ to the washer _B_, which contains a distributor, and thence to the storage gasholder _G_. There is a sludge-cock _F_ at the base of the generator. From the gasholder the gas passes through the purifier _D_, charged with heratol, to the service-pipe.

_Maker_: THE ALLEN CO., 106 VICTORIA STREET, LONDON, S.W.

_Type_: Automatic; water-to-carbide; contact, superposed trays.

The generating plant made by this firm comprises an equalising bell gasholder, from the tank of which water is supplied through a flexible tube to the top of a water-scaled generating chamber in which is a vertical cylinder containing a cage packed with carbide. The open end of the flexible tube is supported by a projection from the bell of the gasholder, so that as the bell rises it is raised above the level of the water in the tank and so ceases to deliver water to the generator until the bell again falls. The water supplied flows by way of the water-seal of the cover of the generating chamber to the cylinder containing the carbide cage. Larger sizes have two generating chambers, and the nozzle of the water delivery-pipe may be switched over from one to the other. There is an overflow connexion which brings the second chamber automatically into action when the first is exhausted. One chamber may be recharged while the other is in action. Spare cylinders and cages are provided for use when recharging. There is a cock for drawing off water condensing in the outlet-pipe from the gasholder. The gas passes from the holder to the lower part of a purifier with water-scaled cover, through the purifying material in which it rises to the outlet leading to the service-pipe. Purifying material under the proprietary name of the "Allen" compound is supplied. The plant is shown in Fig. 44.

Maker: THE BON-ACCORD ACETYLENE GAS CO., 285 KING STREET, ABERDEEN.

Type: Automatic; water-to-carbide; contact, superposed trays.

The "Bon Accord" generating plant made by this firm comprises an equalising displacement gasholder _B_ immersed in a water-tank _A_. Alongside the tank are placed two water-jacketed generating chambers _G1_ and _G2_ containing cages _K_ charged with carbide. Water passes from within the gasholder through the water inlet- pipes _L1 L2_, the cock _H_, and the pipes _F1 F2_ to the generating chambers, from which the gas evolved travels to the holder _B_, in which it displaces water until the water-level falls below the mouths of the pipes _L1_ and _L2_, and so cuts off the supply of water to the generating chambers. The gas passes from the holder _B_ through the pipe with outlet-cock _T_ to a washer containing an acid solution for the neutralisation of ammonia, then through a purifier containing a "special mixture of chloride of lime." After that through a tower packed with lime, and finally through a pressure regulator, the outlet of which is connected to the service-pipe. There is an indicator _I_ to show the amount of gas in the holder. One generator may be charged while the other is in action.

_Maker_: FREDK. BRABY AND CO., LTD., ASHTON GATE WORKS, BRISTOL; AND 352-364 EUSTON ROAD, LONDON.

_Type:_ (I) Automatic; carbide-to-water.

The "A" type of generator made by this firm comprises an equalising bell gasholder, round the bell of which are arranged a series of buckets which are charged with carbide. Those buckets are discharged in turn as the bell falls from time to time through a mechanism operated by a weight suspended from a wire cord on a revolving spindle. The carbide is discharged on to a different spot in the generating tank from each bucket. There is a cock for the periodical removal of sludge. Gas passes through a purifier charged with puratylene to the service-pipe. The disposition of the parts of the plant and the operating mechanism arc shown in the accompanying figure, which represents the generating apparatus partly in elevation and partly in section. The carbide buckets (1) are loosely hooked on the flat ring (2) bolted to the gasholder tank (3). The buckets discharge through the annular water-space (4) between the tank and the generator (5). The rollers (6), fitted on the generator, support a ring (7) carrying radial pins (8) projecting outwards, one pin for each bucket. The ring can travel round on the rollers. Superposed on the ring is a tray (9) closed at the bottom except for an aperture beneath the throat (11), on which is mounted an inclined striker (12), which strikes the projecting tongues (1_a_) of the lids of the buckets in turn. There is fixed to the sides of the generator a funnel (13) with open bottom (13_a_) to direct the carbide, on to the rocking grid (14) which is farther below the funnel than appears from the figure. Gas passing up behind the funnel escapes through a duct (15) to the gasholder. The ring (7) is rotated through the action of the weight (16) suspended by the chain or rope (17) which passes round the shaft (18), which is supported by the bracket (19) and has a handle for winding up. An escapement, with upper limb (20_a_) and lower limb (20_b_), is pivotally centred at (21) in the bracket (19) and normally restrains the turning of the shaft by the weight. There is a fixed spindle (24) supported on the bracket (23)--which is fixed to the tank or one of the guide-rods--having centred on it a curved bar or quadrant (25) running loose on the spindle (24) and having a crank arm (26) to which is connected one end of a rod (27) which, at the other end, is connected to the arm (28) of the escapement. The quadrant bears at both extremities against the flat bar (29) when the bell (22) is sufficiently raised. The bar (29) extends above the bell and carries an arm (30) on which is a finger (30_a_). There is fixed on the shaft (18) a wheel (31), with diagonal divisions or ways extending from side to side of its rim, and stop-pins (32) on one side at each division. A clutch prevents the rotation of the wheel during winding up.

(2) Automatic; water-to-carbide; contact, superposed trays.

The type "B" generator made by this firm comprises an equalising bell gasholder, a crescent-shaped feed water-tank placed on one side of the gasholder, and mechanism for controlling a tap on the pipe by which the feed water passes to a washer whence it overflows through a seal into a horizontal generating chamber containing cells packed with carbide. The mechanism controlling the water feed embodies the curved bar (25), connecting-rod (27) and flat guide-bar (29) as used for controlling the carbide feed in the "A" type of generator (Fig. 46). When the bell descends water is fed into the washer, and the water-level of the seal is thus automatically maintained. The gas evolved passes through a pipe, connecting the seal on the top of the generating chamber with the washer, into the gasholder. Plants of large size have two generating chambers with connexions to a single washer.

_Maker:_ THE DARGUE ACETYLENE GAS CO., 57 GREY STREET, NEWCASTLE-ON- TYNE.

_Type:_ Automatic; water-to-carbide; "drawer."

The "Dargue" acetylene generator made by this firm comprises an equalising bell gasholder _B_ floating in a water-tank _A_, which is deeper than is necessary to submerge the bell of the gasholder. In the lower part of this tank are placed two or more horizontal generating chambers which receive carbide-containing trays divided by partitions into a number of compartments which are half filled with carbide. Water is supplied from the gasholder tank through the tap _E_ and pipe _F_ to the generating chambers in turn. It rises in the latter and floods the first compartment containing carbide before gaining access to the second, and so on throughout the series of compartments. As soon as the carbide in the first generating chamber is exhausted, the water overflows from it through the pipe with by-pass tap _J_ to the second generating chamber. The taps _G_ and _H_ serve to disconnect one of the generating chambers from the water-supply during recharging or while another chamber is in action. The gas evolved passes from each generating chamber through a pipe _L_, terminating in the dip-pipe _M_, which is provided with a baffle-plate having very small perforations by which the stream of gas is broken up, thereby subjecting it to thorough washing by the upper layers of water in the gasholder tank. The washed gas, which thus enters the gasholder, passes from it through the pipe _N_ with main cock _R_ to the service- pipes. The water-supply to the generator is controlled through the tap _E_, which is operated by a chain connected to an arm attached to the bell of the gasholder.

The water in the gasholder tank is accordingly made to serve for the supply of the generating chambers, for the washing of the gas, and as a jacket to the generating chambers. The heat evolved by the decomposition of the carbide in the latter creates a circulation of the water, ensuring thereby thorough mixing of the fresh water, which is added from time to time to replace that removed for the decomposition of the carbide, with the water already in the tank. Thus the impurities acquired by the water from the washing of the gas do not accumulate in it to such an extent as to render it necessary to run off the whole of the water and refill, except at long intervals. A purifier, ordinarily charged with puratylene, is inserted in many cases after the main cock _R_. The same firm makes an automatic generator on somewhat similar lines, specially designed for use in autogenous welding, the smaller sizes of which are readily portable.

_Maker_: J. AND J. DRUMMOND, 162 MARKET STREET, ABERDEEN.

_Type_: Automatic; water-to-carbide; contact.

The generating plant made by this firm comprises two or more generating vessels _B_ in which carbide is contained in removable cases perforated at different levels. Water is supplied to these generating vessels, entering them at the bottom, from an elevated tank _A_ through a pipe _C_, in which is a tap _F_ connected by a lever and chain _L_ with the bell _G_ of the equalising gasholder _H_, into which the evolved gas passes. The lever of the tap _F_ is counter-weighted so that when the bell _G_ descends the tap is opened, and when the bell rises the tap is closed. The gas passes from the generating chambers _B_ through the pipe _D_ to the washer-cooler _E_ and thence to the gasholder. From the latter it passes through the dry purifier _J_ to the service-pipe. The gasholder bell is sealed in oil contained in an annular tank instead of in the usual single-walled tank containing water. The purifying material ordinarily supplied is puratylene. The apparatus is also made to a large extent in a compact form specially for use on board ships.

_Agents_: FITTINGS, LTD., 112 VICTORIA STREET, S.W.

_Type_: Automatic; carbide-to-water.

The "Westminster" generator supplied by this firm is the "Davis" generator described in the section of the United States. The rights for the sale of this generator in Great Britain are held by this firm.

_Maker_: LOCKERBIE AND WILKINSON, TIPTON, STAFFS.

_Type_: (1) Automatic; water-to-carbide; contact, superposed trays.

The "Thorscar" generator of this firm comprises an equalising gasholder, the gas-space of the bell _B_ of which is reduced by conical upper walls. When the bell descends and this lining enters the water in the tank _A_ the displacement of water is increased and its level raised until it comes above the mouths of the pipes _E_, through which a portion then flows to the generators _D_. The evolution of the gas in the latter causes the bell to rise and the conical lining to be lifted out of the water, the level of which thereupon falls below the mouths of the pipes _E_ in consequence of the reduced displacement of the bell. The supply of water to the generators is thus cut off until the bell again falls and the level of the water in the tank is raised above the mouths of the pipes _E_. The generating chambers _D_ are provided with movable cages _F_ in which the carbide is arranged on trays. The gas evolved travels through a scrubbing-box _G_ containing charcoal, and the pipe _J_ with drainage-pipe _P_ to the water-seal or washer _K_ inside the holder, into which it then passes. The outlet-pipe for gas from the holder leads through the condensing coil _L_ immersed in the water in the tank to the condensed water-trap _N_, and thence by the tap _Q_ to the supply-pipe. The generating chambers are water-jacketed and provided with gauge-glasses _H_ to indicate when recharging is necessary, and also with sludge-cocks _M_. The object of the displacement cone in the upper part of the bell is to obtain automatic feed of water to the carbide without the use of cocks or movable parts. There is a funnel- shaped indicator in front of the tank for regulating the height of water to a fixed level, and also an independent purifier, the purifying material or which is supplied under the proprietary name of "Thorlite."

(2) Non-automatic; water-to-carbide; "drawer."

This generating plant, the "Thorlite," comprises a water-tank _A_ from which water is admitted to the drawer generating chambers _B_, one of which may be recharged while the other is in operation. The gas evolved passes through a seal _C_ to the gasholder _D_, whence it issues as required for use through the purifier _E_ to the supply-pipe. For the larger sixes a vertical generating chamber is used. The purifier and purifying material are the same as for the automatic plant of the same firm.

_Maker_: THE MANCHESTER ACETYLENE GAS CO., LTD., ACRE WORKS, CLAYTON, MANCHESTER.

_Type_: Automatic; water-to-carbide; "drawer."

The plant made by this firm comprises an equalising gasholder _A_ from the tank of which water is supplied to generating cylinders _B_ placed at the side of the tank, the number of which varies with the capacity of the plant. The cylinders receive tray carbide-containers divided into compartments perforated at different levels so that they are flooded in turn by the inflowing water. A weight _C_ carried by a chain _D_ from one end of a lever _E_ pivoted to the framing of the gasholder is supported by the bell of the gasholder when the latter rises; but when the holder falls the weight _C_, coming upon the lever _E_, raises the rod _F_, which thereupon opens the valve _G_, which then allows water to flow from the gasholder tank through the pipe _H_ to one of the generating cylinders. When the carbide in the first cylinder is exhausted, the water passes on to a second. One generating cylinder may be recharged while another is in action. The rising of the holder, due to the evolved gas, causes the bell to support the weight _C_ and thus closes the water supply-valve _G_. The gas evolved passes through vertical condensers _J_ into washing- boxes _K_, which are placed within the tank. The gas issues from the washing-boxes into the gasholder bell, whence it is withdrawn through the pipe _L_ which leads to the purifier. Puratylene is the purifying material ordinarily supplied by this firm.

_Maker:_ R,. J. MOSS AND SONS, 98 SNOW HILL, BIRMINGHAM.

_Type:_ (1) Automatic; water-to-carbide; superposed trays.

The "Moss" generator, "Type A," made by this firm comprises an equalising gasholder, four, three, or two generating chambers, and an intermediate water-controlling chamber. Each generating chamber consists of a frame in which are arranged about a central tube trays half filled with carbide, having water inlet-holes at several different levels, and each divided into two compartments. Over this frame is put a bell-shaped cover or cap, and the whole is placed in an outer tank or bucket, in the upper part of which is a water inlet-orifice. The water entering by this orifice passes down the outside of the bell, forming a water-seal, and rises within the bell to the perforations in the carbide trays from the lowest upwards, and so reaches the carbide in successive layers until the whole has been exhausted. The gas evolved passes through the central tube to a water- seal and condensing tank, through which it escapes to the controlling chamber, which consists of a small water displacement chamber, the gas outlet of which is connected to the equalising gasholder. The bell of the equalising gasholder is weighted or balanced so that when it rises to a certain point the pressure is increased to a slight extent and consequently the level of the water in the displacement controlling chamber is lowered. In this chamber is a pipe perforated at about the water-level, so that when the level is lowered through the increased pressure thrown by the rising gasholder the water is below the perforations and cannot enter the pipe. The pipe leads to the water inlet-orifices of the generating tanks and when the equalising gasholder falls, and so reduces the pressure within the controlling chamber, the water in the latter rises and flows through the pipe to the generating tanks. The water supplied to the carbide is thus under the dual control of the controlling chamber and of the differential pressure within the generating tank. The four generators are coupled so that they come into action in succession automatically, and their order of operation is naturally reversed after each recharging. An air-cock is provided in the crown of the bell of each generator and, in case there should be need of examination when charged, cocks are provided in other parts of the apparatus for withdrawing water. There is a sludge-cock on each generator. The gas passes from the equalising gasholder through a purifier, for which the material ordinarily supplied is puratylene.

The "Moss Type B" generator is smaller and more compact than "Type A." It has ordinarily only two generating chambers, and the displacement water controlling chamber is replaced by a bell governor, the bell of which is balanced through a lever and chains by a weight suspended over the bell of the equalising gasholder, which on rising supports this counter-weight and so allows the governor bell to fall, thereby cutting off the flow of water to the generating chambers.

The "Moss Type C" generator is smaller than either "Type A" or "B," and contains only one generating chamber, which is suspended in a pocket in the crown of the equalising gasholder. Water enters through a hole near the top of the bucket of the generating chamber, when it descends with the holder through the withdrawal of gas from the latter.

(2) Semi-automatic; water-to-carbide; superposed trays.

The "Moss Semi-Non-Auto" generating plant resembles the automatic plant described above, but a storage gasholder capable of holding the gas evolved from one charging of the whole of the generating chambers is provided in place of the equalising gasholder, and the generation of gas proceeds continuously at a slow rate.

The original form of the "Acetylite" generator (_vide infra_) adapted for lantern use is also obtainable of R. J. Moss and Sons.

_Maker:_ WM. MOYES AND SONS, 115 BOTHWELL STREET, GLASGOW.

_Type:_ Automatic; carbide-to-water. The "Acetylite" generator made by this firm consists of an equalising gasholder and one or more generating tanks placed alongside it. On the top of each generating tank is mounted a chamber, with conical base, charged with granulated carbide 1/8 to 1/2 inch in size. There is an opening at the bottom of the conical base through which passes a rod with conical head, which, when the rod is lowered, closes the opening. The rod is raised and lowered through levers by the rise and fall of the bell of the equalising gasholder, which, when it has risen above a certain point, supports a counter-weight, the pull of which on the lever keeps the conical feed-valve open. The gas evolved in the generating tanks passes through a condensing chamber situated at the base of the tank into the equalising gasholder and so automatically controls the feed of carbide and the evolution of gas according to the rate of withdrawal of the gas from the holder to the service-pipes. The water in the gasholder tank acts as a scrubbing medium to the gas. The generating tanks are provided with sludge-cocks and a tap for drawing off condensed water. The gas passes from the equalising gasholder, through a purifier and dryer charged with heratol or other purifying material to the service-pipes. The original form of the "Acetylite" generator is shown in elevation and vertical section in Fig. 55. Wm. Moyes and Sons now make it also with a detached equalising gasholder connected with the generator by a pipe in which is inserted a lever cock actuated automatically through a lever and cords by a weight above the bell of the gasholder. Some other changes have been made with a view to securing constancy of action over long periods and uniformity of pressure. In this form the apparatus is also made provided with a clock-work mechanism for the supply of lighthouses, in which the light is flashed on periodically. The flasher is operated through a pilot jet, which serves to ignite the gas at the burners when the supply is turned on to them at the prescribed intervals by the clock- work mechanism.

_Maker_: THE PHÔS CO., 205 AND 207 BALLS POND ROAD, LONDON, N. _Type_: Non-automatic; water-to-carbide; drip.

The type "E" generator made by this firm consists of a generating chamber placed below a water chamber having an opening with cap _E_ for refilling. The generating chamber in closed by a door _B_, with rubber washer _C_, held in position by the rod _A_, the ends of which pass into slots, and the screw _A'_. The movable carbide chamber _D_ has its upper perforated part half filled with carbide, which is pressed upwards by a spring _D'_. The carbide chamber when filled is placed in the generating chamber, which is closed, and the lever _F_ of one of the taps _F'_ is turned from "off" to "on," whereupon water drips from the tank on to the carbide. The evolution of gas is stopped by reversing the lever of the tap. The second tap is provided for use when the evolution of gas, through the water-supply from the first tap, has been stopped and it is desired to start the apparatus without waiting for water from the first tap to soak through a layer of spent carbide. The two taps are not intended for concurrent use. The evolved gas passes through a purifier containing any suitable purifying material to the pipes leading to the burners.

_Maker:_ ROSCO ACETYLENE COMPANY, BELFAST.

_Type:_ Non-automatic; carbide-to-water

The "Rosco" generating plant made by this firm comprises a generating tank _A_ which is filled with water to a given level by means of the funnel-mouthed pipe _B_ and the overflow _O_. On the top of the water-sealed lid of the generating tank is mounted the carbide feed-valve _L_, which consists of a hollow plug-tap with handle _M_. When the handle _M_ is turned upwards the hollow of the tap can be filled from the top of the barrel with carbide. On giving the tap a third of a turn the hollow of the plug is cut off from the outer air and is opened to the generating tank so that the carbide contained in it is discharged over a distributor _E_ on to the tray _N_ in the water in the generating tank. The gas evolved passes through the scrubber and seal-pot _J_ to the storage gasholder _Q_. From the latter the gas passes through the dry purifier _T_ to the service-pipe. A sludge- cock _P_ is provided at the bottom of the generating tank and is stated to be available for use while generation of gas is proceeding. The purifying material ordinarily supplied is "Roscoline."

_Maker_: THE RURAL DISTRICTS GAS LIGHT CO., 28 VICTORIA STREET, S.W.

_Type_: Automatic; water-to-carbide; contact, superposed trays.

The "Signal-Arm" generating apparatus made by this firm comprises a bell gasholder _A_, from the tank _B_ of which water is supplied through a swivelled pipe _C_ to a generating chamber _D_. One end of the swivelled pipe is provided with a delivery nozzle, the other end is closed and counter-weighted, so that normally the open end of the pipe is raised above the level of the water in the tank. A tappet _E_ on the bell of the gasholder comes into contact with, and depresses, the open end of the swivelled pipe when the bell falls below a certain point. As soon as the open end of the swivelled pipe has thus been lowered below the level of the water in the tank, water flows through it into the funnel-shaped mouth _F_ of a pipe leading to the bottom of the generating chamber. The latter is filled with cages containing carbide, which is attacked by the water rising in the chamber. The gas evolved passing into and raising the bell of the gasholder causes the open end of the swivelled pipe to rise, through the weight of the counterpoise _G_, above the level of the water in the tank and so cuts off the supply of water to the generating chamber until the bell again descends and depresses the swivelled pipe. The tappet on the bell also displaces a cap _H_ which covers the funnel-shaped mouth of the pipe leading to the generating chamber, which cap, except when the swivelled supply-pipe is being brought into play, prevents any extraneous moisture or other matter entering the mouth of the funnel. Between the generating chamber and the gasholder is a three-way cock _J_ in the gas connexion, which, when the gasholder is shut off from the generator, brings the latter into communication with a vent-pipe _K_ leading to the open. The gas passes from the holder to a chamber _L_ under grids packed with purifying material, through which it passes to the outlet of the purifier and thence to the service-pipe. Either heratol or chloride of lime is used in the purifier, the lid of which, like the cover of the generator, is water-sealed.

_Maker_: ST. JAMES' ILLUMINATING CO., LTD., 3 VICTORIA STREET, LONDON, S.W.

_Type_: (1) Automatic; water-to-carbide; contact, superposed trays.

This plant consists of the generators _A_, the washer _B_, the equalising gasholder _C_, the purifier _D_, and the water-tank _E_. The carbide is arranged in baskets in the generators to which water is supplied from the cistern _E_ through the pipe _F_. The supply is controlled by means of the valve _H_, which is actuated through the rod _G_ by the rise and fall of the gasholder _C_. Gas travels from the gasholder through the purifier _D_ to the service-pipe. The purifier is packed with heratol resting on a layer of pumice. The washer _B_ contains a grid, the object of which is to distribute the stream of gas through the water. There is a syphon-pot _J_ for the reception of condensed moisture. Taps _K_ are provided for shutting off the supply of water from the generators during; recharging, and there is an overflow connexion _L_ for conveying the water to the second generator as soon as the first is exhausted. There is a sludge-cock _M_ at the base of each generator.

(2) Non-automatic; water-to-carbide; contact, superposed trays.

This resembles the preceding plant except that the supply of water from the cistern to the generators takes place directly through the pipe _N_ (shown in dotted lines in the diagram) and is controlled by hand through the taps _K_. The automatic control-valve _H_ and the rod _G_ are omitted. The gasholder _C_ is increased in size so that it becomes a storage holder capable of containing the whole of the gas evolved from one charging.

_Maker_: THE STANDARD ACETYLENE CO., 123 VICTORIA STREET, LONDON, S.W.

_Type_: (1) Non-automatic; carbide-to-water.

This plant comprises the generator _A_, the washer _B_, the storage gasholder _C_, and the purifier _D_. The generator is first filled with water to the crown of the cover, and carbide is then thrown into the water by hand through the gas-tight lock, which is opened and closed as required by the horizontal handle _P_. A cast-iron grid prevents the lumps of carbide falling into the sludge in the conical base of the generator. At the base of the cone is a sludge-valve _G_. The gas passes from the generator through the pipe _H_ into the washer _B_, and after bubbling through the water therein goes by way of the pipe _K_ into the gasholder _C_. The syphon- pot _E_ is provided for the reception of condensed moisture, which is removed from time to time by the pump _M_. From the gasholder the gas flows through the valve _R_ to the purifier _D_, whence it passes to the service-pipes. The purifier is charged with material supplied under the proprietary name of "Standard."

(2) Automatic; water-to-carbide; contact, superposed trays.

This plant comprises the generators _A_, the washer _B_, the equalising gasholder _C_, the purifier _D_, and the water-tank _E_. The carbide is arranged on a series of wire trays in each generator, to which water is supplied from the water-tank _E_ through the pipe _Y_ and the control-tap _U_. The gas passes through the pipes _H_ to the washer _B_ and thence to the holder _C_. The supply of water to the generators is controlled by the tap _U_ which is actuated by the rise and fall of the gasholder bell through the rod _F_. The gas passes, as in the non-automatic plant, through a purifier _D_ to the service-pipes. Taps _W_ are provided for cutting off the flow of water to either of the generators during recharging and an overflow pipe _h_ serves to convey the water to the second generator as soon as the carbide in the first is exhausted. A sludge-cook _G_ is put at the base of each generator.

(3) Non-automatic; water-to-carbide; contact, superposed-trays.

This apparatus resembles the preceding except that the supply of water to the generators is controlled by hand through the taps _W_, the control valve _U_ being omitted, and the gasholder _C_ being a storage holder of sufficient dimensions to contain the whole of the acetylene evolved from one charging.

_Maker_: THORN AND HODDLE ACETYLENE CO., 151 VICTORIA STREET, S.W.

_Type_: Automatic; water-to-carbide; "drawer."

The "Incanto" generating plant made by this firm consists of a rising bell gasholder which acts mainly on an equaliser. The fall of the bell depresses a ball valve immersed in the tank, and so allows water to flow from the tank past an outside tap, which is closed only during recharging, to a generating chamber. The generating chamber is horizontal and is fixed in the base of the tank, so that its outer case is surrounded by the water in the tank, with the object of keeping it cool. The charge of carbide is placed in a partitioned container, and is gradually attacked on the flooding principle by the water which enters from the gasholder tank when the ball valve is depressed. The gas evolved passes from the generating chamber by a pipe which extends above the level of the water in the tank, and is then bent down so that its end dips several inches below the level of the water. The gas issuing from the end of the pipe is thus washed by the water in the gasholder tank. From the gasholder the gas is taken off as required for use by a pipe, the mouth of which is just below the crown of the holder. There is a lip in the upper edge of the gasholder tank into which water is poured from time to time to replace that consumed in the generation of the gas. There are from one to three generating chambers in each apparatus according to its size. The purifier is independent, and a purifying mixture under the proprietary name of "Curazo" is supplied for use in it.

_Maker:_ WELDREN AND BLERIOT, 54 LONG ACRE, LONDON, W.C.

_Type:_ Automatic; contact.

This firm supplies the "Acétylithe" apparatus (_see_ Belgium).

INDEX

Absorbed acetylene, Acagine, Accidents, responsibility for, Acetone, effect of, on acetylene, solution of acetylene in, Acetylene-copper, Acetylene-oil-gas, Acetylene Association (Austrian)--regulations as to carbide, Acetylene Association (British)--analysis of carbide, generator rules, pressure gauges, purification rules, Acetylene Association (German)--analysis of carbide, holders, generator rules, standard carbide, Acetylene tetrachloride, production of, Ackermann burner, Advantages of acetylene, general, hygienic, intrinsic, pecuniary, "After generation," Air, admission of, to burners, and acetylene, ignition temperature of, composition of, dilution of acetylene with, before combustion, effect of acetylene lighting on, coal-gas lighting on, on illuminating power of acetylene, paraffin lighting on, in acetylene, in flames, effect of, in generators, danger of, objections to, in incandescent acetylene, in service-pipes, proportion of, rendering acetylene explosive, removing, from pipes, specific gravity of, sterilised by flames, Air-gas, and acetylene, comparison between, and carburetted acetylene, comparison between, effect of cold on, illuminating power of, Alcohol, action of, on carbide, for carburetting acetylene, holder seals, from acetylene, production of, Allgemeine Carbid und Acetylen Gesellschaft burner, Alloys, fusible, for testing generators, Alloys of copper. See _Copper (alloyed)_ Aluminium sulphide, in carbide America (U.S.), regulations of the National Board of Fire Underwriters, American gallon, value of, Ammonia, in acetylene, in coal-gas, removal of, solubility of, in water, Analysis of carbide, Ansdell, compressed and liquid acetylene, Anthracene, formation of, from acetylene, Anti-freezing agents, Area of purifiers, Argand burners, Aromatic hydrocarbons, Arrangement of generating plant, Arsenious oxide purifier, Atkins, dry process of generation, Atmospheric moisture and carbide, Atomic weights, Attention needed by generators, Austrian Acetylene Association, regulations as to carbide, Austrian Government Regulations, Autogenous soldering and welding, Automatic generators. See _Generators (automatic)_

B

Baking of carbide Ball-sockets for acetylene, Barium peroxide purifier, sulphate in bleaching-powder, Barrel, gas, for acetylene, quality of Bell gasholders. See _Holders (rising)_ Benz purifying material, Benzene, for carburetting acetylene, production of, from acetylene, Benzine. See _Petroleum spirit_ Bergé, detection of phosphorus, and Reychler, purification of acetylene, and Reychler's reagent, solubility of acetylene in, Bernat, formula for mains and pipes, Berthelot, addition of chlorine to acetylene, sodium acetate, sulphuric acid and acetylene, Berthelot and Matignon, thermochemical data, and Vieille, dissolved acetylene, Billwiller burners, Black, acetylene, Blagden, sodium hypochlorite, Bleaching-powder purifier (simple), Blochmann, copper acetylide, Blow-off pipes. See _Vent-pipes_ Blowpipe, acetylene, Boiling-ring, Boistelle. See _Molet_ Borek, enrichment of oil-gas, _Bougie décimale_, Brackets for acetylene, Bradley, Read, and Jacobs, calcium carbophosphide, Brame and Lewes, manganese carbide, Bray burners, British Acetylene Association. See _Acetylene Association (British)_, Fire Offices Committee Regulations, regulations. See _Acetylene Association (British); Home Office; Orders in Council_ Bromine-water purifier, Bullier, effect of heat on burners, phosphorus in acetylene, and Maquenne purifier, Bunsen burner, principle of, Bunte, enrichment of oil-gas, Burner orifices and gas density, Burners, atmospheric, principle of, design of, glassware for, heating, incandescent, Ackermann, Allgemeine Carbid und Acetylen Gesellschaft, Bray, firing back in, Fouché, Günther's, illuminating power of, Jacob, Gebrüder, Keller and Knappich, Knappich, O.C.A., pressure for, principles of construction of, Schimek, Sirius, Trendel, typical, Weber, Zenith, self-luminous, Argand, as standard of light, Billwiller, Bray, choking of, corrosion of, cycle, Falk, Stadelmann and Co.'s, Konette, Phôs, Wiener's, Dolan, Drake, effect of heat on, Elta, Falk, Stadelmann and Co.'s, firing back in, fish-tail, Forbes, Hannam's, illuminating power of, self-luminous injector, Javal, Kona, Luta, Naphey, Orka, Phôs, Pintsch, pressure for, rat-tail, Sansair, Schwarz's, Stadelmann, Suprema, twin, angle of impingement in, injector, non-injector, warping of, Wiener's, Wonder, By-products, See also _Residues_

C

Cadenel, shape of incandescent acetylene mantle, "Calcidum," Calcium carbide, action of heat on, action of non-aqueous liquids on, analysis of, and carbon bisulphide, reaction between, and hydroxide, reaction between, and ice, reaction between, and steam, reaction between, and water, reaction between, as drying material, baking of, balls and cartridges. See _Cartridges_ bulk of, chemical properties of, crushing of, decomposition of, by solids containing water, heat evolved during, imperfect, speed of, temperature attained during, deterioration of, on storage, drums of, dust in, explosibility of, fire, risk of, formula for, granulated, heat-conducting power of, of formation of, impurities in, inertness of, in residues, physical properties of, purity of, quality, regulations as to, sale and purchase of, regulations as to, scented, shape of lumps of, sizes of, small, yield of gas from, specific gravity of, heat of, standard, British, German, "sticks," storage regulations for, subdivided charges of, sundry uses of, swelling of, during decomposition, "treated," yield of acetylene from, Calcium carbophosphide, Calcium chloride, cause of frothing in generators, for seals, purifier, solubility of acetylene in, Calcium hydroxide, adhesion of, to carbide, and carbide, reaction between, milk of, solubility of acetylene in, physical properties of, space occupied by, Calcium hypochlorite, Calcium oxide, and water, reaction between, hydration of, hygroscopic nature of, physical properties of, Calcium phosphide, Calcium sulphide, Calorie, definition of, Calorific power of acetylene, various gases, Candle-power. See _Illuminating power_ Capelle, illuminating power of acetylene, Carbide. See _Calcium carbide_ Carbide-containers, air in, filling of, partitions in, water-jacketing, Carbide-feed generators. See _Generators (carbide-to-water)_ Carbide impurities in acetylene, Carbide-to-water generators. See _Generators (carbide-to-water)_ Carbides, mixed, Carbolic acid, production of, from acetylene, Carbon, combustion of, in flames, deposition of, in burners, gaseous, heat of combustion of, heat of combustion of, vaporisation of, pigment, production of, Carbon bisulphide and acetylene, reaction between, and calcium carbide, reaction between, in coal-gas, Carbon dioxide, addition of, to acetylene, dissociation of, effect of, on explosibility of acetylene, for removing air from pipes, heat of formation of, produced by respiration, benzene, coal-gas, in flame of acetylene, Carbon monoxide, in acetylene, heat of combustion of, formation of, temperature of ignition of, Carbonic acid. See _Carbon dioxide_ Carburetted acetylene, composition of, effect of cold on, illuminating power of, manufacture of, pecuniary value of, Carburetted water-gas, enrichment of, Carburine. See _Petroleum spirit_ Carlson, specific heat of carbide, Caro, acetone vapour in acetylene, addition of petroleum spirit to generator water, air in incandescent acetylene, calorific power of gases, colour of incandescent acetylene, composition of mantles, durability of mantles, heat production in generators, illuminating power of carburetted acetylene, of incandescent acetylene, oil of mustard, silicon in crude acetylene, Caro and Saulmann, "Calcidum," Carriage, cost of, and artificial lighting, Cartridges of carbide, Cast-iron pipe for acetylene, Castor oil for acetylene joints, Catani, temperature of acetylene flame, Caustic potash purifier, Cedercreutz, yield of gas from carbide, and Lunge, purification, Ceilings, blackening of, Ceria, proportion of, in mantles, Cesspools for residues, Chandeliers, hydraulic, for acetylene, Charcoal and chlorine purifier, Charging generators after dark, at irregular intervals, Chassiron lighthouse, Chemical formulæ, meaning of, Chemical reactions and heat, of acetylene, Chimneys for stoves, &c., glass, for burners, Chloride of lime. See _Bleaching-powder_ Chlorine and acetylene, compounds of, and charcoal purifier, in acetylene, Chromic acid purifier, Cigars, lighted, danger of, Claude and Hess, dissolved acetylene, Coal-gas, enrichment of, with acetylene, illuminating power of, impurities in, vitiation of air by, Cocks, hand-worked, in generators, Coefficient of expansion of acetone, air, dissolved acetylene, gaseous acetylene, liquid acetylene, simple gases, Coefficient of friction of acetylene, of coal-gas, Coke filters for acetylene, Cold, effect of, on acetylene, on air-gas, on carburetted acetylene, on generation, Colour judging by acetylene, of acetylene flame, of air-gas flame, Colour of atmospheric acetylene flame, of coal-gas flame, of electric light, of incandescent acetylene flame, of spent carbide, Combustion of acetylene, deposit from, Composition pipe for acetylene, Compounds, endo- and exo-thermic, explosive, of acetylene and copper, "Compounds," of phosphorus and sulphur, silicon, Compressed acetylene, Condensed matter in pipes, removal of, Condensers, Connexions, flexible, for acetylene, Construction of generators, principles of, regulations as to, Contact generators, Convection of heat, Cooking-stoves, Copper acetylide, (alloyed) in acetylene apparatus, (unalloyed) in acetylene apparatus, and acetylene, reactions between, carbides, chloride purifier Corrosion in apparatus, avoidance of, Corrosive sublimate purifier, as test for phosphorus Cost of acetylene lighting, Cotton-wool filters for acetylene, Council, Orders in. See _Orders in Council_ Counterpoises for rising holders, Couples, galvanic, Coward. See _Dixon_ Critical pressure and temperature of acetylene, Crushing of carbide, "Cuprene," Cuprous chloride purifier, Cycle lamps, burners for, dilute alcohol for, Cylinders for absorbed acetylene,

D

Davy, addition of chlorine to acetylene, Davy's lamp for generator sheds, Decomposing vessels. See _Carbide containers_ Decomposition of acetylene, of carbide, See _Calcium carbide (decomposition of)_ De Forcrand, heat of formation of carbide, Density. See _Specific gravity_ Deposit at burner orifices, on reflectors from combustion of acetylene, Deterioration of carbide in air, Diameter of pipes and explosive limits, Diaphragms, flexible, in generators, Diffusion through gasholder seals, Diluted acetylene, Dimensions of mains and pipes, Dipping generators, Displacement gasholders. See _Holders (displacement)_ Dissociation of acetylene, carbon dioxide, water vapour, Dissolution of acetylene, depression of freezing-point by, of gas in generators, Dissolved acetylene, Dixon and Coward, ignition temperature of acetylene, of various gases, Dolan burners, Doors of generator sheds, Drainage of mains, Drake burners, Driers, chemical, Dripping generators, Drums of carbide, Dry process of generation, Dufour, addition of air to acetylene, "Dummies" in gasholder tanks, Dust and incandescent lighting, in acetylene, carbide,

E

Effusion of gases, Eitner, explosive limits of acetylene, and Keppeler, estimation of phosphine, phosphorus in crude acetylene, Electric lamps in generator sheds, lighting, cost, and efficiency of, Elta burner, Endothermic compounds, nature of acetylene, Engines, use of acetylene in, Enrichment, value of acetylene for, with acetylene, épurène purifying material, Equations, chemical, meaning of, Erdmann, acetylene as a standard of light, colour of acetylene flame, production of alcohol, Ethylene, formation of from acetylene, heats of formation and combustion of, ignition temperature of, Exhaustion of air by flames, Exothermic compounds, Expansion of gaseous acetylene, coefficient of, of liquid acetylene coefficient of, various coefficients of, Explosibility of carbide, Explosion of chlorine and acetylene, of compressed acetylene, Explosive compounds of acetylene and copper, effects of acetylene dissociation, limits, meaning of term, of acetylene, of various gases, nature of acetylene, wave, speed of, in gases, Expulsion of air from mains,

F

Faced joints for acetylene, Falk, Stadelmann and Co., boiling-ring, burners, cycle-lamp burner, Ferric hydroxide purifier, Fery, temperature of flames, and Violle, acetylene as standard of light, Filters for acetylene, Filtration, Fire Offices Committee Regulations (British), risks of acetylene apparatus, carbide, flame illuminants, Underwriters, United States, Regulations, "Firing back" in incandescent burners, self-luminous burners, Fish, action of lime on, Fittings for acetylene, quality of, Flame, colour of, air-gas, atmospheric acetylene, coal-gas, incandescent, acetylene, self-luminous acetylene, Flame illuminants, risk of fire with, of acetylene containing air, steadiness of acetylene, Flame temperature of acetylene, temperature of various gases, Flames, distortion of, by solid matter, effect of air on, nitrogen on, evolution of heat in, light in, jumping of, liberation of carbon from, loss of heat from, shading of acetylene, size of, Flare lamps, Flash-point of paraffin, Flexible connexions for acetylene, Floats in holder seals, Flooded-compartment generators, Flow of gases in pipes, Flues for heating burners, Fog, transmission of light through, Forbes burner, Foreign regulations, Formulæ, meaning of chemical, Fouché, absorbed acetylene, burner, dissolved acetylene, illuminating power of acetylene air mixtures, incandescent acetylene, liquid acetylene, oxy-acetylene blowpipe, Fournier. See _Maneuvrier_ Fowler, enrichment of oil-gas, Fraenkel, deposit on reflectors from combustion of acetylene, silicon in acetylene, France, regulations of the Conseil d'Hygiène de la Seine, village acetylene mains in, Frank, freezing-point of calcium chloride solutions, preparation of black pigment, purifier, Frankoline, Freezing of generators, of holder seals, Freezing of portable lamps, of pressure-gauges, Freezing-point, depression of by dissolution of acetylene, of calcium chloride solutions, of dilute alcohol, of dilute glycerin, Freund and Mai, copper acetylide, Friction of acetylene, coefficient of, coal-gas, coefficient of, gas in pipes, Frost, effect of, on air-gas, on carburetted acetylene, Froth, lime, in acetylene, Frothing in generators, Fuchs and Schiff, olive oil, Furnace gases for removing air from pipes,

G

Gallon, American, value of, Galvanic action, Garelli and Falciola, depression of freezing-point by dissolution of acetylene, Gas barrel for acetylene, objection to, drying of, engines, acetylene for, escape of, from generators, firing, effects of, volumes, correction of, for temperature and pressure, yield of, from carbide, determining, standard, Gases, calorific value of, effusion of, explosive limits of, flame temperature of, illuminating power of, inflammable properties of, speed of explosive wave in, temperature of ignition of, Gasfitters' paint, Gasholders. See _Holders_ Gatehouse, F. B., test-papers, J. W., estimation of phosphine, Gaud, blocking of burners, polymerisation of acetylene, Generation, dry process of, Generating plant, regulations as to construction of, Generator impurities in acetylene, pressure, utilisation of, sheds, lighting of, smoking in, water, addition of bleaching-powder to, of petroleum spirit to, Generators and holders, isolation of, attention needed by, Generators, charging after dark, chemical reactions in, construction of, copper in, corrosion in, dissolution of gas in, effect of tarry matter in, escape of gas from, failure of, for analytical purposes, for welding, frothing in, frozen, thawing of, gauge of sheet-metal for, heat dissipation in, economy in, produced in, high temperatures and impurities in, instructions for using, joints in, making, "lagging" for, lead solder in, materials for construction of, maximum pressure in, output of gas from, overheating in, polymerisation in, pressure in, protection of, from frost, purchase of, regulations as to, American (National Board of Fire Underwriters), Austrian Government, British Acetylene Association, Fire Offices Committee, Home Office Committee(1901), French (Council d' Hygiene de la Seine), German Acetylene Association, Hungarian Government, Italian Government, responsibility for accidents with, selection of, temperatures in, typical, vent-pipes for, waste-pipes for, water-jackets for, water-scale in, Generators (automatic), advantages of, carbide-to-water, definition of, flexible diaphragms for, holders of, interlocking in, mechanism for, pressure thrown by, speed of reaction in, store of gas in, supply of water to, use of oil in, water-to-carbide, worked by holder bell, by pressure, Generators (carbide-to-water), advantages of, frothing of, grids for, loss of gas in, maximum temperature in, pressure in, quantity of water required by, Generators (contact), (dipping), temperatures in, (dripping), temperatures in, (flooded compartment), (non-automatic), advantages of, carbide-to-water, hand-charging of, water required for, definition of, speed of reaction in, water-to-carbide, (portable), (shoot), (water-to-carbide), overheating in, with carbide in excess, with water in excess, Gerard, silicon in crude acetylene, Gerdes, acetylene copper, German Acetylene Association. (See _Acetylene Association, German_) Gin, heat of formation of carbide, Glassware, for burners, Glow-lamps, electric, in generator sheds, Glucose for treatment of carbide, Glycerin for holder-seals, for wet meters, Governor, displacement holder as, Governors, Graham, effusion of gases, Gramme-molecules, Granjon, illuminating power of self-luminous burners, phosphine in acetylene, pressure, purifier, Granulated carbide. See _Calcium carbide, (granulated)_ Graphite, artificial, production of, Grease for treatment of carbide, Grids for carbide-to-water generators, in purifiers, Grittner, acetylene, and copper, Guides for rising holders, Güntner burner,

H

Haber, effect of heat on acetylene, Haldane, toxicity of sulphuretted hydrogen, Hammcrschmidt, correction of gas volumes, and Sandmann, milk of lime, Hannam's Ltd., burners, Hartmann, acetylene flame, Haze, on combustion of acetylene, Heat absorbed during change of physical state, action on acetylene. See _Overheating_ carbide, and temperature, difference between, conducting power of carbide iron and steel, water, convected, developed by acetylene lighting, coal-gas lighting, electric lighting, paraffin lighting, dissipation of, in generators, economy in generators, effect of, on acetylene. (See _Overheating_) on burners, evolution of, in flames, expansion of gaseous acetylene by, liquid acetylene by, from acetylene, production of, latent. See _Latent heat_ loss of, from flames, of chemical reactions, of combustion of acetylene, carbon, carbon monoxide, ethylene, of formation of acetylene, calcium carbide, hydroxide, oxide, carbon dioxide, monoxide, ethylene, water, of hydration of calcium oxide, of reaction between carbide and calcium hydroxide, between carbide and water, of solution of calcium hydroxide, of vaporisation of carbon, water, radiant, specific. See _Specific heat_ Heating apparatus for generator sheds, Hefner unit, Heil, atmospheric acetylene flame, carburetted acetylene, Heise, acetylene flame, Hempel, enrichment of coal-gas, Heratol, Hess. See _Claude_ Hexachlorethane, production of, High houses, supply of acetylene to, Holder-bells, for testing mains, supplying water to automatic generators, weighting of, Holder-seals, freezing of, level of liquid in, liquids in, and pressure, solubility of acetylene in, use of floats in, liquids in, for decomposing carbide, oil in, water in, for washing the gas, Holders (gas) and generators, isolation of, and pressure, relationship between, and purifiers, relative position of, exposed, roofs over, false interiors for, freezing of, gauge of sheet-metal for, loss of pressure in, moistening of gas in, of automatic generators, preservation of, from corrosion, situation of, size of, vent-pipes for, value of, Holders (displacement), action of, pressure given by, (rising), guides and counterpoises for, pressure thrown by, equalisation of, tanks for, Home Office, maximum pressure permitted by, prohibition of air in acetylene by, Committee, 1901, recommendations, report, Home Secretary's Orders. See _Orders in Council_ Hoxie. See _Stewart_, Hubou, acetylene black, Hungarian rules for apparatus, Hydraulic pendants for acetylene, Hydrocarbons formed by polymerisation, illuminating power of, volatile, names of, Hydrochloric acid in purified acetylene, Hydrogen and acetylene, reactions between, effect of, on acetylene flame, ignition temperature of, in acetylene, liberated by heat from acetylene, silicide in crude acetylene, Hygienic advantages of acetylene,

I

Ice, reaction between carbide and, Ignition temperature of acetylene, various gases, Illuminating power and illuminating effect, definition of, of acetylene, after storage, carburetted, effect of air on, incandescent, nominal, self-luminous, of acetylene-oil-gas, of air-gas, of polymerised acetylene, of candles, of coal-gas, of electric lamps, of hydrocarbons, various, of paraffin, Illumination, amount of, required in rooms, of lighthouses, of optical lanterns, Impurities in acetylene, carbide, detection and estimation of, effect of, on air, generator, harmfullness of, water soluble, See also _Ammonia_ and _Sulphuretted hydrogen_ in coal-gas, in purified acetylene, maximum limits of, Incandescent acetylene, burners. See _Burners (incandescent)_ mantles, Inertness of carbide, Inflaming-point of acetylene, Inflammability, spontaneous, Installations, new, removal of air from, Interlocking of automatic generators, Iron and acetylene, reactions between, and steel, heat-conducting power of, silicide in carbide, Insecticide, carbide residues as, Isolation of apparatus parts, Intensity, specific, of acetylene light, of oil light, Italian Government rules,

J

Jackets for generators, Jacob, Gebrüder, burner, Jacobs. See _Bradley_ Jaubert, arsenious oxide purifier, Javal burners, blocking of, purifier, Jet photometer of acetylene, Joint-making in generators, pipes,

K

Keller and Knappich burner, Keppeler, lead chromate in acagine, Keppeler, purification, silicon in acetylene, test-papers, See also _Eitner_ Kerosene. See _Paraffin oil_ Klinger, vent-pipes, Knappich burner, Kona burner, Konette cycle-lamp burner,

L

La Belle boiling ring, Labour required in acetylene lighting, Lagging for generators, Lamps for generator sheds paraffin, portable, acetone process for, Landolt-Börnstein, solubility of acetylene in water, Landriset. See _Rossel_ Lantern, optical, illumination of, Latent heat, Lead chromate in bleaching-powder, objection to, in generators, pipes for acetylene, salts in bleaching-powder, wire, &c., for faced joints, Leakage of acetylene, Leaks, search for, Le Chatelier, explosive limits, temperature of acetylene flame, thermo-couple Leduc, specific gravity of acetylene, Lépinay, acetylene for engines, Level alteration and pressure in mains, Lewes, ammonia in crude acetylene, blocking of burners, haze, heat of decomposition of carbide, production in generators, illuminating power of acetylene, phosphorus in crude acetylene, polymerisation of acetylene, presence of hydrogen and carbon monoxide in acetylene, reaction between carbide and calcium hydroxide, silicon in crude acetylene, temperature of acetylene flame, Lewes and Brame, manganese carbide, Lidholm, estimation of phosphine, Lifebuoys, acetylene for, Lifetime of burners, mantles, Lifting power of acetylene in holders, Light, acetylene as a standard of, colour of acetylene, incandescent, self-luminous, evolution of, in flames, from acetylene, production of, transmission of through fog, Lights, single, disadvantages of, strong and weak, comparison between, Lighthouse illumination, Lighting by acetylene, scope of, of generator sheds, Lime dust in acetylene, reaction with sodium carbonate, sludge. See _Residues_ solubility of, in sugar solutions, water, solubility of gas in, Lime-light, acetylene for the, Limits, explosive, of acetylene, Lindé-air, Linseed oil for acetylene joints, Liquid acetylene, properties of, condensation in pipes, in holder-seals and pressure, in pressure-gauge, Liquids, corrosive action of, on metals, for seals, purification by, solubility of acetylene in, Locomotive lighting, Loss of gas in generators, of pressure in holders, in mains, in purifiers, on distribution, Love, enrichment by acetylene, Lubricating oil for seals, Luminous burners. See _Burners, self-luminous_ Lunge and Cedercreutz, determination of phosphorus in acetylene, purification, Luta burner, Lutes for holders. See _Seals_

M

Mahler, temperature of flames, Mai and Freund, copper acetylide, Mains, deposition of liquid in, diameter of, and explosive limits, dimensions of, escapes from, friction in, laying of, lead, quality of, removing air from, testing of, Make of acetylene from carbide, in generators, Manchester burners, Maneuvrier and Fournier, specific heat of acetylene, Manganese carbide, Mantles for acetylene, Manure for generator protection, Manurial value of generator residue, Maquenne. See _Bullier_ Marsh gas, enrichment with acetylene, formed from acetylene, Matignon. See _Berthelot_, Mauricheau-Beaupré, épurène, estimation of phosphine, frothing in generators, phosphine in acetylene, silicon in acetylene, Mechanism for automatic generators, Mercaptans in acetylene, Mercuric chloride purifier, test for phosphorus, Merck test-papers, Metals for generators, gauge of, Meters for acetylene, Methane, enrichment with acetylene, formed from acetylene, ignition temperature of, Methylated spirit for generators, for holder seals, Meyer and Münch, ignition temperatures, Mildew in vines, use of acetylene in, Milk of lime, solubility of acetylene in, Mineral oil for lighting. (See _Paraffin oil_) for seals, Miner's lamp for generator sheds, Mist, transmission of light through, Mixter, thermo-chemical data, Mixtures of acetylene and air, illuminating duty of, Moisture, effect of, on carbide, in acetylene, Molecular volume of acetylene, weight of acetylene, weights, various, Molet-Boistelle acetylene-air mixture, Morel, formula for acetylene pipes, sodium plumbate purifier, specific heat of acetylene, of carbide, Mosquitoes, destruction of, Moths, catching of, Motion of fluids in pipes, Motors, acetylene for, Münch. See _Meyer_ Münsterberg, acetylene flame, Mustard, oil of,

N

Naphey burners, Naphthalene, formation of, from acetylene, Neuberg, illuminating power of acetylene, radiant efficiency of acetylene, Nieuwland, mixtures of acetylene and chlorine, Nichols, illuminating power of acetylene after storage, temperature of acetylene flame, Nickel and acetylene, reactions between, Nipples, burner, materials for, Nitrides in carbide, Nitrogen in flames, effect of, Non-automatic generators. See _Generators (non-automatic)_ Non-luminous acetylene flame, appearance of, burners. See _Burners (atmospheric)_ Non-return valves,

O

O. C. A. burner, Odour of acetylene, Oil, action of, on carbide, castor, for acetylene joints, in generators, in residues, in seals, linseed, for acetylene joints, mustard, olive, for seals, (See also _Paraffin oil_) Olive oil for seals, Oil-gas, enrichment of, Optical efficiency of acetylene, Orders in Council, air in acetylene, compression of absorbed acetylene, acetylene-oil-gas, neat acetylene, Origin of petroleum, Orka burner, Ortloff, friction of acetylene, Overheating in generators, See also _Polymerisation_ Oxide of iron purifier, Oxy-acetylene blowpipe, Oxygen required for combustion of acetylene, of benzene, combustion of acetylene with, flames burning in,

P

Paint, cause of frothing in generators, gas-fitters', Paraffin oil, action of, on carbide, flash-point of, illuminating power of, in residues, lamps, lighting, effect of on air, heat developed by, quality of different grades of, use of in automatic generators, seals, Paraffin wax, treatment of carbide with, Partial pressure, Pendants, water-slide for acetylene, Petroleum oil. See _Paraffin oil_ spirit, addition of, to generator water, composition of, for carburetted acetylene, spirits, nomenclature of, theory of origin of, Pfeiffer, purifier, Pfleger, puratylene, Phenol, production of, from acetylene, Phôs burners, Phosphine, cause of deposit at burner orifices, composition of, in crude acetylene, amount of, toxicity of, Phosphoretted hydrogen. See _Phosphine_ Phosphorus and incandescent mantles, "compounds," in crude acetylene, in purified acetylene, detection and determination of, removal of, "Phossy-jaw," Photometer, jet of acetylene, Phylloxera, use of acetylene for, Physical properties of acetylene, Pickering, freezing-points of calcium chloride solutions, Pictet, freezing-points of dilute alcohol, purification of acetylene, Pintsch burners, Pipes, blow-off. See _Vent-pipes_ diameter of, and explosive limits, vent. See _Vent-pipes_ (See also _Mains_) Plant, acetylene, fire risks of, order of items in, Platinum in burners, Poisonous nature of acetylene, Pole, motion of fluids in pipes, pressure thrown by holders, Polymerisation, definition of, of acetylene, See also _Overheating_ Porous matter, absorption of acetylene in, Portable lamps, acetone process for, temperature in, Potassium bichromate purifier, hydroxide purifier, permanganate purifier, Power from acetylene, production of, Precautions with generators, with new installations, Presence of moisture in acetylene, Pressure and leakage, after explosions of acetylene, atmospheric, automatic generators working by, correction of gas volumes for, critical, of acetylene, definition of (gas), for incandescent burners, self-luminous burners, gauge, liquid for, given by displacement holders, rising holders, in generators, utilisation of, in mains and pipes, in purifiers, loss of, irregular, caused by vent-pipes, maximum safe, for acetylene, necessity for regular, partial, regulators. See _Governors_ Protection of generators from frost, holders from frost, Puratylene, Purchase of a generator, carbide, regulations as to, Purification by liquids and solids, in portable lamps, necessary extent of, reasons for, regulations as to, speed of, Purified acetylene, chlorine in, hydrochloric acid in, phosphorus in, sulphur in, Purifiers and holder, relative positions of, construction of, duplication of, exhaustion of, foul, emptying of, loss of pressure in, mechanical, for acetylene, Purifying materials, density of, efficiency of, quantity required, Pyralid, destruction of the,

Q

Quality of carbide, regulations as to, Quicklime. See _Calcium oxide_

R

Radiant efficiency of acetylene, heat, Railway lighting by acetylene, Ramie mantles for acetylene, Range of explosibility, meaning of term, of acetylene, Rat-tail burner, Reactions between copper and acetylene, chemical, of acetylene, physical, of acetylene, Reaction grids in generators, Read and Jacobs. See _Bradley_ Rod lead for acetylene joints, Regulations, American (National Board of Fire Underwriters of U.S.A.), Austrian Acetylene Association, Government, British Acetylene Association, Fire Offices Committee, Home Office Committee (1901), for analysis of carbide, for construction of generating plant, for generators, for purification, for sale and purchase of carbide, for sampling carbide, for storing carbide, French (Conseil d'Hygiène de la Seine), German Acetylene Association, Hungarian Government, Italian Government, Residue from dry process of generation, Residues, carbide in, colour of, composition of, consistency of, disposal of, containing oil, manurial value of, utilisation of, Respiration of acetylene, Reversibility of reaction between calcium oxide and water, Reychler. See _Bergé_ Rising holders. See _Holders (rising)_ Rossel and Landriset, ammonia in crude acetylene, purifier, sulphur in crude acetylene, Roofs over exposed holders, Rooms, amount of illumination required in, Rubber tubes for acetylene, Ruby for burners, Rules. See _Regulations_

S

Safety lamp, Davy's, for generator sheds, valves. See _Vent-pipes_ Sale of carbide, regulations as to, Salt, common, in holder-seals, Salzbergwerk Neu Stassfurt, production of tetrachlorethane, Sampling carbide, Sandmann. See _Hammerschmidt_ Sansair burner, Saulmann. See _Caro_ Sawdust in bleaching-powder, Scale, water, in generators, Scented carbide, Schiff. See _Fuchs_ Schimek burner, Schwander, carburetted acetylene, Schwarz burners, Seal-pots, Seals (holder). See _Holder-seals_ Seams in generator-making, Self-luminous burners. See _Burners (self-luminous)_ Sensible heat, Separation of holder from generator, Service-pipes. See _Mains_ Shoot generators, Silicon compounds, in acetylene, in carbide, Sirius burner, Slaked lime. See _Calcium hydroxide_ Sludge. See _Residues_ Sludge-cocks, automatic locking of, Sludge-pipes, blocked, clearance of, Smell of crude and purified acetylene, Smith, purification, Smoke, production of, by flames, Smoking, danger of, in generator sheds, Soap, use of, in testing pipes, Soda, washing, for decomposing carbide, Sodium acetate solution for generator jackets, Sodium carbonate and lime, reaction between, crystallised, for decomposing carbide, chloride for holder-seals, solubility of acetylene in, hypochlorite purifier, plumbate purifier, sulphate in bleaching-powder, Soil, carbide residues as dressing for, Solder in generators, Soldering, autogenous, Solids containing water, decomposition of carbide by, purification by, Solubility of acetylene, in generators, in holders, in liquids, Soot, production by, of flames, Space occupied by purifying materials, Sparks from steel tools, danger of, Specific gravity and holder pressure, leakage, of acetylene, dissolved, gaseous, liquid, of air, of carbide, of gases, and burner construction, of water, heat of acetylene, of carbide, heats, various, intensity. See _Intensity, specific_ Speed of reactions between carbide, water, and calcium hydroxide, of purification, Spent lime. See _Residues_ Spontaneous inflammability, Spraying apparatus, Stable manure for warming generators, Stadelmann burners, Standard of illumination in rooms, of light, acetylene as, Steam, latent heat of, use of, specific heat of, reaction between carbide and, Steam-barrel for acetylene mains, Steatite for burners, Steel, heat-conducting power of, tools, danger of Sterilisation of air by flames, Stewart and Hoxie, radiant efficiency of acetylene, Storage regulations for carbide, vessels for carbide, temporary, Styrolene. formation of, from acetylene, Suckert. See _Willson_ Suffocation by acetylene, Sugar solutions, solubility of lime in, Sulphur "compounds," in coal-gas, in crude acetylene, in purified acetylene, removal of, Sulphuretted hydrogen, solubility of, in water, toxicity of, Sulphuric acid and acetylene, reactions between as purifying material, Superficial area in purifiers, Supply of water to automatic generators, Suprenia burners, Swelling of carbide during decomposition, Symbols, chemical, meaning of, Syphons for removing water,

T

Table-lamps, acetone process for, Tabular numbers, Tanks for rising holders, construction of, "Tantalus Cup," Taps for acetylene pipes, Tar, cause of frothing in generators, Tarry matter in generators, Telescopic gasholders. _See Holder (rising)_ Temperature and heat, difference between, correction of volumes for, critical, of acetylene, high, effect of, on acetylene. See _Polymerization_ of acetylene blowpipe, flame, of dissociation of acetylene, of ignition of acetylene, various gases, of reaction between carbide and calcium hydroxide, between carbide and water, Temperatures in generators, calculation of, determination of, Tension of liquid acetylene, Test-papers, Tetrachlorethane, production of, Tetrachloride, acetylene, production of, Thawing of frozen apparatus, Thermo-chemical data, Thermo-couple, Le Chatelier's, Thomson, radiant efficiency of acetylene, thermo-chemical data, Tools, steel or iron, danger of, Town supplies, Toxicity of acetylene, of sulphur and phosphorus compounds, Train-lighting by acetylene, Treated carbide. See _Calcium carbide (treated)_ Trondol burner, Tubes, diameter of, and explosive limits, Tubes for acetylene. See _Mains_ Tubing, flexible, for acetylene, Typical generators,

U

Ullmax purifier, Unaccounted-for gas, Underwriters, United States Fire, United States. See _America_ Uses, sundry, for acetylene,

V

Valuation of carbide, Value of acetylene, hygienic, enriching, pecuniary, of purifying materials, Valves, screw-down, for generators, Vapour, water, in acetylene, objections to, removal of, value of, Vehicular lamps, Ventilation of generator sheds, Vent-pipes, economy of, for carbide vessels, generators, holders, noise in, position of mouths of, size of, Vibration and incandescent lighting, Vieille, dissolved acetylene, Vigouroux, silicon in acetylene, Village installations, mains for, leakage in, supplies, Villard, liquid acetylene, Vines, treatment by acetylene of, for mildew and phylloxera, Violle and Féry, acetylene as standard of light, Vitiation of air by flames, Volume, alteration of, on dissociation, and weight of acetylene, molecular, of acetylene, Volume of acetylene passing through pipes, Volumes, gas, correction for temperature and pressure,

W

Washers, oil, water, Waste-pipes of generators, Water and calcium oxide, reaction between, and carbide, heat of reaction between, boiling-point, evolution of gas at, condensation of, in pipes, consumption of, in generators, convection currents in, freezing-point, evolution of gas at, heat absorbed in warming, conducting power of, of formation of, in excess, generators with, in holders, freezing of, use for decomposition, use for washing, jackets for generators, quality of, for portable generators, quantity required in carbide-to-water generators, scale in generators, solubility of acetylene in, of impurities in, of load in, specific gravity of, supply for automatic generators, non-automatic generators, yield of gas per unit of, Water-gas, enrichment with acetylene, Water-seals, as not-return valves, setting water-level in, Water-slide pendants for acetylene, Water-soluble impurities in acetylene, See also _Ammonia and Sulphuretted hydrogen_ Water-to-carbide generators. See _Generators (water-to-carbide)_ Water-vapour, dissociation of, existence of, at low temperatures, in acetylene, objections to, removal of, value of, reaction between carbide and, Weber burner, Wedding, enrichment of coal-gas, Weed-killer, carbide residues as, Weight and volume of acetylene, Weights, atomic, molecular, Welding, acetylene, White lead, for acetylene joints, Wiener burners, Willgerodt, purification, Willson and Suckert, liquid acetylene, Windows in generator sheds, Winter, manipulation of generators during, Wöhler, addition of chlorine to acetylene, Wolff, acetone in acetylene, illuminating power of acetylene, purifier, silicon in acetylene, Wonder burner, Work done in actuating automatic generators,

Y

Yield of gas, deficient, cause of, from carbide, determining, (British standard), (German standard), from water,

Z

Zenith burner,

INDEX TO APPENDIX

A

"A" Generator (of Braby and Co., Ltd.), "A1" generator (of Acetylene Corporation of Great Britain), "A-to-Z" generator (of Acetylene Corporation of Great Britain), Acetylene Corporation of Great Britain, Acetylene Gas and Carbide of Calcium Co., Acetylene Illuminating Co., Ltd., "Acetylite" generator, "Acétylithe" generator, Acétylithe, Soc. An. de l', Allen Co., "Allen" Flexible-tube generator, "Allen" purifying material, American generators, Applications de l'Acétylène, La Soc. des., Austrian generator, Automatic generators,

B

"B" generator (of Braby and Co., Ltd.), Belgian generators, Bon Accord Acetylene Gas Co., "Bon Accord" generator, Braby, Frederick and Co., Ltd., British generators,

C

Canadian generators, Carbide-to-water generators, "Carburlen" purifying material, Chloride of lime purifying material, Colt Co., J. G., "Colt" generator, Compartment, flooded, generator, Contact generators, Cork waste and wadding purifying material, "Corporation Flexible Tube Generator," "Curaze" purifying material,

D

"Dargue" generator, Dargue Acetylene Gas Co., Davis Acetylene Co., "Davis" generator, Debruyne, L., Debruyne's generators, Drawer generators, Drip generator, Drummond, J. and J.,

E

English generators,

F

Flooded compartment generator, Fittings, Ltd., Frankoline purifying material, French generators,

G

German generators,

H

Heratol, purifying material,

I

"Incanto" generator, Irish generator,

J

"Javal" generator,

K

Keller and Knappich, G.m.b.H., "Klenzal" purifying material, Klinger, Rich., Klinger's generator, "Knappich" generator,

L

"L'Éclair" generator, "L'Étoile" generator, L'Hermite, Lockerbie and Wilkinson,

M

Manchester Acetylene Gas Col., Ltd., Mangiameli, Fr. and Co., Moss, R. J. and Sons, "Semi-Non-Auto" generator, "Type A" generator, "Type B" generator, "Type C" generator, Moyes Wm., and Sons,

N

Non-automatic generators, Nordische Azetylen Industrie,

O

"Omega" generator, Overberge, De Smet van, "Owens" generator, "Owens" purifying material,

P

Phôs Co., "Phôs Type E" generator, "Photolithe" generator, Photolithe, Soc. An. Belg de la, Pumice purifying material, Puratylene purifying material, Purifying material, "Allen," "Carburylen," chloride of lime, coke and cotton, chemically treated, cork waste and wadding, "Curaze," frankoline, heratol, "Klenzal," "Owens," pumice, puratylene, "Roscoline," "Standard," "Thorlite,"

R

Rosco Acetylene Co., "Rosco" generator, "Roscoline" purifying material, Rural Districts Gas Light Co.,

S

St. James' Illuminating Co., Ltd., Scotch generators, Semi-automatic generator, Siche Gas Co., Ltd., "Siche" generator, "Signal-Arm" generator, "Sirius" generator, Sirius, Maison, Standard Acetylene Co., "Standard" purifying material, Sunlight Gas Machine Co., Superposed pans or trays,

T

"Thorlite" generator, purifying material, Thorn and Hoddle Co., "Thorscar" generator, Trays, superposed,

U

United States generators,

W

Wadding and cork waste purifying material, Water-to-carbide generators, Weldhen and Bleriot, Welsh generator, "Westminster" generator,