Chapter 8

The applications are multitudinous. In the first place, in certain difficult cases, it may serve for the observation of a swinging thermometer, which is then read during its motion. Then it may be employed for the continuous observation of a body submitted to centrifugal force. Apropos of this, we desire to add a few words. Most of the forces at our disposal, applied to a body, are transmitted from molecule to molecule, and produce tension, crushing, etc. Gravity and magnetic attraction form an exception; their point of application is found in all the molecules of the body, and they produce pressures and slidings of a peculiar kind. But these forces are of a very limited magnitude; but it might nevertheless be of great interest to amplify them in a strong measure. Let us, for example, suppose that a magician has found a means of increasing the intensity of gravity tenfold in his laboratory. All the conditions of life would be modified to the extent of being unrecognizable. A living being borne in this space would remain small and squat. All objects would be stocky and be spread out in width or else be shattered. Viscid or semi-solid bodies, such as pitch, would rapidly spread out and take on a surface as plane and smooth as water under the conditions of gravity upon the earth. On still further increasing the gravity, we would see the soft metals behaving in the same way, and lead, copper and silver would in turn flow away. These metals, in fact, are perfectly moulded under a strong pressure, just like liquids, through the simple effect of the attraction of the earth applied to all their molecules. Upon causing an adequate attractive force to act upon the molecules of metals they will be placed under conditions analogous to those to which they are submitted in strong presses or in the mills that serve for coining money. The sole difference consists in the fact that the action of gravity is infinitely more regular, and purer, from a physical standpoint, than that of the press or coining mill. Through very simple considerations, we thus reach the principle which was enunciated, we believe, by the illustrious Stokes, that our idea of solid and liquid bodies is a necessary consequence of the intensity of gravity upon the earth. Upon a larger or smaller planet, a certain number of solid bodies would pass to a liquid state, or inversely. Let us return to the cyclostat. In default of gravity, centrifugal force gives us a means of realizing certain conditions that we would find in the laboratory of our magician. The cyclostat permits us to observe what is going on in that laboratory without submitting ourselves to forces that might cause us great annoyance. We have hitherto been content to put poor frogs therein and study upon them the effect of the central anæmia and peripheral congestion produced on their organism by the unrestrained motion of the liquids carried along by centrifugal force. The results, it seems, have proved very curious.--_La Nature_.

* * * * *

MERCURY WEIGHING MACHINE.

We illustrate herewith a novel type of weighing machine. Hitherto the weighing machines in common use have either been designed with some kind of steelyard apparatus, upon which weights could be moved to different distances from a fixed fulcrum, or springs have been so applied as to be compressed to different degrees by different weights put upon the scale pan, or table, of the machine. In other instances more complicated mechanism is used, and various movable counterpoises are usually required in order to balance the moving parts of the machine.

The type of machine which we now illustrate has been recently brought out by Mr. G.E. Rutter, and the system has given very satisfactory results with platform weighing machines. The engraving illustrates a form of balance which may be applied to strength testing machines, or for any work where an apparatus of the type of a Salter's balance would be of use. It is simple in construction, and consists of a tube A closed at the bottom and forming a reservoir for mercury. The body which it is required to weigh is hung upon the hook B carried by the crossbar C, which is connected by rigid rods to the upper part of the tube, and by means of the internal rods D is attached to the cross head E, which works freely inside the tube A. The top part of the tube is, as will be clearly understood from the illustration, cut away to allow of the descent of the rods. To the cross head E is attached the piston F, which may be made of wood or of a hollow metal tube closed at the end, or other suitable material. It will be easily understood that when a weight is hung upon the hook B, the piston F is caused to descend into the mercury which rises in the annular space between the piston and the tube. The weight of the volume of displaced mercury is proportional to the weight of the body hung upon the hook, and the buoyancy of the piston in the mercury forms the upward force which balances the downward pull of gravity. When the apparatus is at rest the piston F descends into the mercury to such a distance as will balance the weight of the rods, hook, and piston itself. If, now, the cross bar G, provided with a pointer H, be fixed to the rods, it should at that time register zero, upon the scale J fixed to the outside of the tube, and as the descent of the piston into the mercury is directly proportional to the weight of the body attached to the hook B, the divisions of the scale will all be equal. It will thus be seen that the apparatus is extremely simple in theory, and it only remains to construct it in such a form that the mercury may not easily be spilt in moving the instrument from place to place. This is effected by causing the cross head E to fill the tube while working freely therein, and a small valve is arranged to allow for the passage of air. The cross bar G can be regulated upon the rods by means of set screws.--_Industries._

* * * * *

REEFING SAILS FROM THE DECK.

While this method may be applied to topsails and top-gallant-sails, I especially apply it to courses, which, being so difficult to reef the old way, may by this method be reefed from the deck in a few minutes.

After several years of trial by myself and others, on voyages around Cape Horn under all circumstances of weather, of sleet and snow, this method has always given the utmost satisfaction.

The average time required for reefing and setting was noted for five years, being seven and one-half minutes.

This trial was made on a mainsail, the yard being seventy-one feet long, and reefyard sixty-six feet long, eleven inches diameter at center and nine at yard-arms.

By reference to the drawing it will be seen that it is not necessary to have clewgarnets or buntlines in reefing. The operation is performed by easing of the sheet and hauling the lee reef-tackle first, also the midship reef tackle.

When the yardarm of the reefspar is up at the lee side, the sail cannot sag to leeward when the tack is eased away. Now haul the weather reef-tackle likewise midship, snug up to the yard, belay all down the tack, and sheet aft.

As all the reef-tackles lead to the slings of the yard, there is no impediment in swinging the yard when the reef-tackles are taut and belayed.

The slack sail will not chafe, as it remains quiet, but if so desired may be stopped up at leisure with only a few hands with stops provided for that purpose.

In case of a sudden squall the sail may be hauled up the usual way. The buntlines will draw the part of the sail below the reef well up on the part above the reefyard, and remain becalmed, while the weight of the reefspar will prevent any slatting or danger of losing the sail any more than any other sail clewed up.

In case there is steam power at hand, all three reef-tackles may be hauled simultaneously, easing sheet and tack sufficiently to let the wind out of the sail without shaking.

There are other advantages gained by this method; while its essentials are positive, quick reefing from the deck in all weathers, it is also better reefed than by the old method. For by this new method the sail is not strained or torn, and the sail will wear longer, not being subject to such straining.

It may be carried longer, as the spar supports the sail like a band, especially an old sail.

This method does not interfere with the use of the so called midship-tack, but change of putting on bands, from the leech of the sail at the reef to the center tack would be necessary.

The weight of the spar may be considered by some as objectionable, (an old argument against double-topsail yards). The spar used for the reef may be about one-half the diameter of the yard on which it is to be used.

Such critics do not consider that a crew of men aloft on the yard are several times heavier than such a spar.

L.K. MORSE.

Rockport, Me., Oct. 28, 1891.

* * * * *

A NEW PROCESS FOR THE BLEACHING OF JUTE.

By Messrs. LEYKAM and TOSEFOTHAL.

Jute is well known as a very cheap fiber, and its employment in textile industry is consequently both extensive and always increasing. Accompanying this increase is a corresponding one in the amount of old waste jute, which can be employed for the manufacture of paper.

Up to the present time, only very little use has been made of jute for the manufacture of thread and the finer fabrics, because the difficulty of bleaching the fiber satisfactorily has proved a very serious hindrance to its improvement by chemical means. All the methods hitherto proposed for bleaching jute are so costly that they can scarcely be made to pay; and, moreover, in many cases, the jute is scarcely bleached, and loses considerably in firmness and weight, owing to the large quantities of bleaching agents which have to be applied.

In consequence of this difficulty, the enormous quantities of jute scraps, which are always available, are utilized in paper making almost entirely for the production of ordinary wrapping paper, which is, at the best, of medium quality. In the well known work of Hoffmann and Muller, the authors refer to the great difficulty of bleaching jute, and therefore recommend that it be not used for making white papers.

Messrs. Leykam and Tosefothal have succeeded in bleaching it, and rendering the fiber perfectly white, by a new process, simple and cheap (which we describe below), so that their method can be very advantageously employed in the paper industry.

The jute fiber only loses very little of its original firmness and weight; but, on the other hand, gains largely in pliability and elasticity, so that the paper made from it is of great strength, and not only resists tearing, but especially crumpling and breaking.

The jute may be submitted to the process in any form whatever, either crude, in scraps, or as thread or tissue.

The material to be bleached is first treated with gaseous chlorine or chlorine water, in order to attack the jute pigment, which is very difficult to bleach, until it takes an orange shade. After having removed the acids, etc., formed by this treatment, the jute is placed in a weak alkaline bath, cold or hot, of caustic soda, caustic potash, caustic ammonia, quicklime, sodium or potassium carbonate, etc., or a mixture of several of these substances, which converts the greatest part of the jute pigment, already altered by the chlorine, into a form easily soluble in water, so that the pigment can be readily removed by a washing with water. After this washing the jute can be bleached as easily as any other vegetable fiber in the ordinary manner, by means of bleaching powder, etc., and an excellent fibrous material is obtained, which can be made use of with advantage in the textile and paper industries.

The application of the process may be illustrated by an example:

One hundred kilos. of waste jute scraps are first of all treated in the manner usually employed in the paper industry; 15 per cent. of quicklime is added, and they are treated for 10 hours at a pressure of 1½ atmospheres. The scraps are then freed from water by means of a hydro-extractor, or a press, and finally saturated with chlorine in a gas chamber for 24 hours or less, according to the requirements of the case. Every 100 kilos. of jute requires 75 kilos. of hydrochloric acid (20° B.) and 20 kilos. of manganese peroxide (78-80 per cent.).

The jute then takes an orange color, and is subsequently washed in a tank, a kilo. of caustic soda being added per 100 kilos. of jute; this amount of alkali is sufficient to dissolve the pigment, which colors the water flowing from the washer a deep brown. After washing, the jute can be completely bleached by the use of 5-7 kilos. of bleaching powder per 100 kilos. of jute.--_Mon. de la Teinture_.

* * * * *

THE INDEPENDENT--STORAGE OR PRIMARY BATTERY--SYSTEM OF ELECTRIC MOTIVE POWER.[1]

[Footnote 1: Abstract of a paper read before the American Streel Railway Association, Oct. 23, 1891.]

By KNIGHT NEFTEL.

Owing to a variety of causes, the system which was assigned to me at the last convention to report on has made less material progress in a commercial way than its competitors.

PRIMARY BATTERIES.

So far, primary batteries have been applied only to the operation of the smallest stationary motors. Their application in the near future to traction may, I think, be entirely disregarded. Were it not a purely technical matter, it might be easily demonstrated, with our knowledge of electro-chemistry, that such an arrangement as an electric primary battery driving a car is an impossibility.

In view of the claims of certain inventors, I regret to be obliged to make so absolute a statement; but the results so far have produced nothing of value.

SECONDARY BATTERIES.

The application of secondary or storage batteries to electrical traction has been accomplished in a number of cities, with a varying amount of success. Roads equipped by batteries have now been sufficiently long in operation to allow us to draw some conclusions as to the practical results obtained and what is possible in the near future. The advantages which have been demonstrated on Madison Avenue, in New York; Dubuque, Iowa; Washington, D.C., and elsewhere, may be summarized as follows:

_First_. The independent feature of the system. The cars independent of each other, and free from drawbacks of broken trolley wires; temporary stoppages at the power station; the grounding of one motor affecting other motors, and sudden and severe strains upon the machinery at the power station, such as frequently occur in direct systems; the absence of all street structures and repairs to the same, and the loss by grounds and leakages, are also very considerable advantages, both as to economy and satisfactory operation.

_Second_. The comparatively small space required for the power station. Each car being provided with two or more sets of batteries, the same can be charged at a uniform rate without undue strain on the machinery of the power station, and as it can be done more rapidly than the discharge required for the operation of the motors, a less amount of general machinery is necessary for a given amount of work.

Another and important advantage of the system is the low pressure of the current used to supply the motors, and the consequent increased durability of the motor, and practically absolute safety to life from electrical shock.

It has been demonstrated also that the cars can be easily handled in the street; run at any desired speed, and reversed with far more safety to the armature of the motor than in the direct system. The increased weight requires simply more brake leverage.

The modern battery, improved in many of its details during the last year, is still an unknown quantity as to durability. There is the same doubt concerning this as there was at the time incandescent lamps were first introduced. At that time some phenomenal records were made by lamps grouped with other lamps.

Similarly, some plates appeared to be almost indestructible, while others, made practically in the same manner, deteriorate within a very short time. It is, consequently, very difficult to exactly and fairly place a limit on the life of the positive plates as yet. Speaking simply from observation of a large number of plates of various kinds, I am inclined to put the limit at about eight months; though it is claimed by some of the more prominent manufacturers--and undoubtedly it is true in special cases--that entire elements have lasted ten months, and even longer.

It must be remembered, however, that the jolting and handling to which these batteries are subjected, in traction work, increases the tendency to disintegrate, buckle and short circuit, and that the record for durability for this application can never be the same as for stationary work. A serious inconvenience to the use of batteries in traction work is the necessary presence of the liquid in the jars. This causes the whole equipment to be somewhat cumbersome, and unless arranged with great care, and with a variety of devices lately designed, a source of considerable annoyance.

The connections between the plates, which formerly gave so much trouble by breaking off, have been perfected so as to prevent this difficulty, and the shape of the jars has been designed to prevent the spilling of the acid while the car is running. The car seats are now practically hermetically sealed, so that the escaping gases are not offensive to the passengers.

The handling of the batteries is an exceedingly important consideration. Many devices have been invented to render this easy and cheap. I have witnessed the changing of batteries in a car, one set being taken out and a charged set replaced by four men in the short space of three minutes. This is accomplished by electrical elevators, which move the batteries opposite the car, and upon the platforms of which the discharged elements are again charged.

The general conclusions which the year's experience and progress have afforded us an opportunity to make may be summarized as follows:

Storage battery cars are as yet applicable only to those roads which are practically level; where the direct system cannot be used, and where cable traction cannot be used; and applicable to those roads only at about the same cost as horse traction.

I feel justified in making this statement in view of the guarantees which some of the more prominent manufacturers of batteries are willing to enter into, and which practically insure the customer against loss due to the deterioration of plates: leaving the question of the responsibility of the company the only one for him to look into.

* * * * *

ON THE ELIMINATION OF SULPHUR FROM PIG IRON.[1]

[Footnote 1: Paper read before the Iron and Steel Institute.]

By J. MASSENEZ, Hoerde.

If in the acid and the basic Bessemer processes the molten pig iron is taken direct to the converter from the blast furnace, there is the disadvantage that the running of the individual blast furnaces can hardly ever be kept so uniform as it is desirable should be the case in order to secure regularity in the converter charges. In the manufacture of Bessemer steel the variable proportions of silicon and of carbon here come chiefly under consideration, while in the basic process it is chiefly the varying proportions of silicon and of sulphur; and in cases where either ores containing variable percentages of phosphorus, or puddle slags, are treated, the varying proportion of phosphorus has also to be considered. This disadvantage of the irregular composition of the individual blast furnace charges is obviated in a simple and effective manner by W.R. Jones's mixing process. In this as much pig iron from the various blast furnaces of a works as is sufficient for a large number of Bessemer charges, say from seven to twelve charges, or, in other words, from 70 to 120 tons of pig iron, is placed in a mixing vessel. Only a portion of pig iron placed in the mixer is taken for further treatment for steel, while new supplies of pig iron are brought from the blast furnace. In this way homogeneity sufficient for practical purposes is obtained.

In the treatment of phosphoric pig iron, which is employed in the production of basic steel, it is, however, not sufficient merely to conduct the molten pig iron in large quantities to the converter in a mixed condition, but the problem here is to render the proportion of sulphur also independent of the blast furnace process to such an extent that the proportion of sulphur in the finished steel is so low that the quality of the steel is in no way influenced by it. The question of desulphurization has, especially of late years, become of the utmost importance, at any rate for the iron industry of the Continent. By the great strike of 1889, the German colliers have succeeded in greatly improving their wages; and with this increase in wages not only is there a distinct diminution in the amount of coal wrought, but, unfortunately, the coal produced since then is raised in a much less pure condition than was formerly the case. Consequently the proportion of sulphur in the coke has considerably increased. Whereas formerly this proportion did not exceed one per cent., it has now in many cases risen to 18 per cent.; so that an unpleasant ratio exists between the wages of the workmen and the amount of sulphur in the coal raised. It is therefore not remarkable that, even when ores fairly free from sulphur are treated, it easily happens that a sulphureted pig iron is obtained.

In order to effect satisfactory desulphurization, attention has been bestowed on the fact that iron sulphide is converted by manganese into manganese sulphide and iron. If sulphureted pig iron, poor in manganese, is added in a fluid condition to manganiferous molten pig iron, poor in sulphur, the metal is desulphurized, and a manganese sulphide slag is formed. It may be urged that it does not seem necessary to effect the desulphurization by means of the reaction of the manganese and iron sulphide outside of the blast furnace, as it is possible, by suitably directing the blast furnace, by the employment of manganiferous ores or highly basic slag, so to desulphurize the iron in the blast furnace itself that it would be unnecessary further to lower the percentage of sulphur. Every blast furnace manager, however, will have observed that, even with every precaution in the blast furnace practice, pig iron will often be obtained with so high a percentage of sulphur as to render it useless for the Bessemer acid or basic processes. If the desulphurization in the blast furnace is carried sufficiently far, it is always necessary to work the furnace hot, and thus to obtain hotter iron than is desirable for further treatment in the converter. On the other hand, the method of further desulphurization outside the blast furnace, described in this paper, presents the double advantage that part of the blast furnace can be kept cooler, and thus lime and coke be saved, and that there is a certainty that no red-short charges are obtained in the treatment in the converter, while the pig iron passes to the converter at a suitable temperature.