Chapter 5

We herewith illustrate an exceedingly simple form of detecter, to show if the night watchmen perform their visits regularly and punctually. In the case, C, is a clockwork apparatus driving the axle, S, at the end of which is a worm which gears into the wheel of the drum, D. The rotation of D, thus obtained unrolls a strip of paper from the other drum, D. This paper passes over the poles of as many electro-magnets as there are points to be visited, and underneath the armatures of these electro-magnets. Each armature has a sharp point fixed on its under side, and when a current passing through the coils causes the attraction of the armature, this point perforates the paper. The places to be visited are connected electrically with the binding screws shown, and the watchman has merely to press a button to make the electric circuit complete. It has been found in practice that plain paper answers every purpose, as the clock giving an almost uniform motion enables the reader, after having seen the perforated slips once or twice, to determine fairly well the time which elapses between each pressure of the button.--_The Engineer._

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INTEGRATING APPARATUS.

At a recent meeting of the London Physical Society, Mr. C. Vernon Boys read a paper on "Integrating Apparatus." After referring to his original "cart" machine for integrating, described at a former meeting of the society, he showed how he had been led to construct the new machine exhibited, in which a cylinder is caused to reciprocate longitudinally in contact with a disk, and give the integral by its rotation. Integrators were of three kinds: (1) radius machines; (2) cosine machines; (3) tangent machines. Sliding friction and inertia render the first two kinds unsuitable where there are delicate forces or rapid variation in the function to be integrated. Tangent machines depend on pure rolling, and the inertia and friction are inappreciable. They are, therefore, more practical than the other sort. It is to this class that Mr. Boys' machines belong. The author then described a theoretical tangent integrator depending on the mutual rolling of two smoke rings, and showed how the steering of a bicycle or wheelbarrow could be applied to integrate directly with a cylinder either the quotient or product of two functions. If the tangent wheel is turned through a right angle at starting, the machine will integrate reciprocals, or it can be made to integrate functions by an inverse process. If instead of a cylinder some other surface of evolution is employed as an integrating surface, then special integrations can be effected. He showed a polar planimeter in which the integrating surface is a sphere. A special use of these integrators is for finding the total work done by a fluid pressure reciprocating engine. The difference of pressure on the two sides of the piston determines the tangent of the inclination of the tangent wheel which runs on the integrating cylinder; while the motion of the latter is made to keep time with that of the piston. In this case the number of evolutions of the cylinder measures the total amount of work done by the engine. The disk cylinder integrator may also be applied to find the total amount of work transmitted by shafting or belting from one part of a factory to another. An electric current meter may be made by giving inclination to the disk, which is for this purpose made exceedingly small and delicate, by means of a heavy magnetic needle deflected by the current. This, like Edison's, is a direction meter; but a meter in which no regard is paid to the direction of the current can be made by help of an iron armature of such a shape that the force with which it is attracted to fill the space between the poles of an electro-magnet is inversely as its displacement. Then by resisting this motion by a spring or pendulum the movement is proportional to the current, and a tangent wheel actuated by this movement causes the reciprocating cylinder on which it runs to integrate the current strength. Mr. Boys exhibited two such electric energy meters, that is, machines which integrate the product of the current strength by the difference of potential between two points with respect to time. In these the main current is made to pass through a pair of concentric solenoids, and in the annular space between these is hung a solenoid, the upper half of which is wound in the opposite direction to the lower half. By the use of what Mr. Boys calls "induction traps" of iron, the magnetic force is confined to a small portion of the suspended solenoid, and by this means the force is independent of the position. The solenoid is hung to one end of a beam, and its motion is resisted by a pendulum weight, by which the energy meters may be regulated like clocks to give standard measure. The beam carries the tangent wheels, and the rotation of the cylinder gives the energy expanded in foot-pounds or other measures. The use of an equal number of turns in opposite directions on the movable solenoid causes the instrument to be uninfluenced by external magnetic forces. Mr. Boys showed on the screen an image of an electric arc, and by its side was a spot of light, whose position indicated the energy, and showed every flicker of the light and fluctuation of current in the arc. He showed on the screen that if the poles are brought too near the energy expended is less, though the current is stronger, and that if the poles are too far apart, though the electromotive force is greater the energy is less; so that the apparatus may be made to find the distance at which the greatest energy, and so the greatest heat and light, may be produced.

At the conclusion of the paper, Prof. W.G. Adams and Prof. G.C. Foster could not refrain from expressing their high admiration of the ingenious and able manner in which Mr. Boys had developed the subject.

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A CANAL BOAT PROPELLED BY AIR.

A novelty in canal boats lies in Charles River, near the foot of Chestnut street, which is calculated to attract considerable attention. It is called a pneumatic canal boat and was built at Wiscasset, Me., as devised by the owner, Mr. R.H. Tucker, of Boston, who claims to hold patents for its design in England and the United States. The specimen shown on Charles River, which is designed to be used on canals without injuring the banks, is a simple structure, measuring sixty-two feet long and twenty wide. It is three feet in depth and draws seventeen inches of water. It is driven entirely by air, Root's blower No. 4 being used, the latter operated by an eight-horse-power engine. The air is forced down a central shaft to the bottom, where it is deflected, and, being confined between keels, passes backward and upward, escaping at the stern through an orifice nineteen feet wide, so as to form a sort of air wedge between the boat and the surface of the water. The force with which the air strikes the water is what propels it. The boat has a speed of four miles an hour, but requires a thirty-five-horsepower engine to develop its full capabilities. The patentee claims a great advantage in doing away with the heavy machinery of screws and side-wheels, and believes that the contrivance gives full results, in proportion to the power employed. It is also contrived for backing and steering by air propulsion. Owing to the slight disturbance which it causes to the water, it is thought to be very well adapted for work on canals without injury to the sides.--_Boston Journal._

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HEAD LININGS OF PASSENGER CARS.

The veneer ceilings are considered as much superior to cloth as cloth was to the roof-ceiling. They are remarkably chaste, and so solid and substantial that but little decoration is necessary to produce a pleasing effect. The agreeable contrast between the natural grain of the wood and the deeper shade of the bands and mouldings is all that is necessary to harmonize with the other parts of the interiors of certain classes of cars--smoking and dining cars, for example. But in the case of parlor and dining-room cars, the decorations of these ceilings should be in keeping with the style of the cars, by giving such a character to the lines, curves, and colors, as will be suggestive of cheerfulness and life. While these head linings are deserving of the highest commendation as an important improvement upon previous ones, they are still open to some objections. One barrier to their general adoption is their increased cost. It is true that superior quality implies higher prices, but when the prices exceed so much those of cloth linings, it is difficult to induce road managers to increase expenses by introducing the new linings, when the great object is to reduce expenses. Another objection to wood linings is their liability to injury from heat and moisture, a liability which results from the way in which they are put together. A heated roof or a leak swells the veneering, and in many cases takes it off in strips. To obviate these objections, I have, during the past eighteen months, been experimenting with some materials that would be less affected by these causes, and at the same time make a handsome ceiling. About a year ago I fitted up one car in this way, and it has proved a success. The material used is heavy tar-board pressed into the form of the roof and strengthened by burlaps. It is then grained and decorated in the usual manner, and when finished has the same appearance as the veneers, will wear as well, and can be finished at much less cost.--_D.D. Robertson._

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IMPROVED MORTAR MIXER.

The engravings herewith illustrate a new form of mixing or pugging machine for making mortar or any other similar material. It has been designed by Mr. R.R. Gubbins, more especially for mixing emery with agglutinating material for making emery wheels; and a machine is at work on this material in the manufactory of the Standard Emery Wheel Company, Greek Street, Soho. The machine is shown in perspective in Fig. 1 with the side door of the mixing box let down as it is when the box is being emptied; and in Fig. 2 it is shown in transverse section. The principle of the machine is the employment of disks fixed at an angle of about 45 deg. on shafts revolving in a mixing box, to which a slow reciprocating movement of short range is given.

In our illustrations, C is a knife-edge rail, upon which run grooved wheels supporting the pugging box. To the axle of one grooved wheel a connecting rod from crank arm, F is attached to effect the to-and-fro motion of the mixing box, B. G is the door of the box, B, hinged at H, and secured by hinged pins carrying fly nuts. A cover and hopper and also a trap may be supplied to the box, B, for continuously feeding and discharging the material operated upon. L, L, are the pugging blades or discs on shafts, M. The shafts, M, pass through a slot in the box, B, and the packing of these shafts is effected by the face plate sliding and bearing against the face on the standard of the machine. P is a guide piece on the standard, against which bears and slides the piece, Q, bolted on to box, B, to support and guide the box, B, in its movement. The forked ends of a yoke engage with the collars, S, on the shafts, M, this yoke being set by a screw so that the shafts may be easily removed. The machine is driven from the pulleys and shaft, T, through gearing, T2 and T3, and by the Ewart's chain on the wheel and pinion, V and U.--_The Engineer._

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[Continued from SUPPLEMENT, No. 311, page 4960.]

PRACTICAL NOTES ON PLUMBING.[1]

[Footnote 1: From the London _Building News_.]

BY P.J. DAVIES, H.M.A.S.P., ETC.

TINNING IRON PIPES, COPPER OR BRASS-WORK, BITS, ETC.

Previously, I described the method of tinning the bit, etc., with resin; but before this work on joints can be considered complete, I find it necessary to speak of tinning the ends of iron pipes, etc., which have within the last fifty years been much used in conjunction with leaden pipes. This is done as follows: Take some spirits of salts (otherwise known as hydrochloric acid, muriatic acid, hydrogen chloride, HCl), in a gallipot, and put as much sheet-zinc in it as the spirit will dissolve; you have then obtained chloride of zinc (ZnCl). A little care is required when making this, as the acid is decomposed and is spread about by the discharged hydrogen, and will rust anything made of iron or steel, such as tools, etc. It also readily absorbs ammoniacal gas, so that, in fact, sal ammoniac may also be dissolved in it, or sal ammoniac dissolved in water will answer the purpose of the chloride of zinc.

Having the killed spirits, as it is sometimes called, ready, file the end of your iron or bit and plunge this part into the spirits, then touch your dipped end with some fine solder, and dip it again and again into the spirits until you have a good tinned face upon your iron, etc.; next you require a spirit-brush.

SPIRIT-BRUSH.

You can make this by cutting a few bristles out of a broom or brush, push them into a short piece of compo tube, say 1/4 in., and hammer up the end to hold the bristles; next cut the ends of the bristles to about 3/8 in. long, and the brush is ready for use.

SOLDERING IRON TO LEAD.

Suppose you want to make a joint round a lead and iron pipe. First file the end of your iron pipe as far up as you would shave it if it were lead, and be sure to file it quite bright and free from grease; heat your soldering-iron; then, with your spirit-brush, paint the prepared end of your iron, and with your bit, rub over the pipe plenty of solder, until the pipe is properly tinned, not forgetting to use plenty of spirits; this done, you can put your joint together, and wipe in the usual manner. Caution.--Do not put too much heat on your iron pipe, either when tinning or making the joint, or the solder will not take or stand.

DUMMIES FOR PIPE-BENDING.

Figs. 38 and 38B. This tool I had better describe before proceeding to the method of bending. To make it take a piece of, say, ½ in. iron pipe, 3 ft. long, or the length required, bent a little at one end, as shown at A B in Fig. 38 and Fig. 38B. Tin the end about 2 in. up, make a hole with a small plumbing-iron in some sand, and place the tinned end of the iron pipe, B, into this hole; fill the hole up with good hot lead, and the dummy, after it has been rasped up a little, is ready for use. It will be found handy to have three or four different lengths, and bent to different angles, to suit your work. A straight one (Fig. 38B.) made to screw into an iron socket or length of gas-pipe, will be found very handy for getting dents out of long lengths of soil-pipe.

BENDS AND SET-OFFS.

Before you begin bending solid pressed pipes always put the thickest part of your pipe _at the back_. Lead, in a good plumber's hands, may be twisted into every conceivable shape; but, as in all other trades, there is a right and a wrong way of doing everything, and there are many different methods, each having a right and wrong way, which I shall describe. I shall be pleased if my readers will adopt the style most suitable for their particular kind of work; of course I shall say which is the best for the class of work required.

For small pipes, such as from ½ in. to 1 in. "_stout_ pipe," you may pull them round without trouble or danger; but for larger sizes, say, from 1¼ in. to 2 in., some little care is necessary, even in stout pipes.

Fig. 37 illustrates a badly made bend, and also shows how it comes together at the throat, X, and back, E; L is the enlarged section of X E, looking at the pipe endways. The cause of this contraction is pulling the bend too quickly, and too much at a time, without dressing in the sides at B B as follows: After you have pulled the pipe round until it just begins to flatten, take a soft dresser, or a piece of soft wood, and a hammer, and turn the pipe on its side as at Fig. 37; then strike the bulged part of the pipe from X B toward E, until it appears round like section K. Now pull your pipe round again as before, and keep working it until finished. If you find that it becomes smaller at the bend, take a long bolt and work the throat part out until you have it as required.

BENDING WITH WATER (LIGHT PIPES).

Fig. 39. This style of bending is much in use abroad, but not much practiced in London, though a splendid method of work.

It is a well known fact that, practically speaking, for such work, water is incompressible, but may be turned and twisted about to any shape, provided it is inclosed in a solid case--Fig. 39 is that case. The end, A, is stopped, and the stopcock, B, soldered into the other end. Now fill up this pipe quite full with warm water and shut the cock, take the end, A, and pull round the pipe, at the same time dressing the molecules of lead from the throat, C, toward D E, which will flow if properly worked.

You can hammer away as much as you please, but be quick about it, so that the water does not cool down, thereby contracting; in fact, you should open the cock now and then, and recharge it to make sure of this.

SAND BENDING.

This is a very old method of bending lead pipes, and answers every purpose for long, easy bends. Proceed in this way: The length of the pipe to be 5 ft., fill and well ram this pipe solid with sand 2 ft. up, then have ready a metal-pot of very hot sand to fill the pipe one foot up, next fill the pipe up with more cold sand, ramming it as firmly as possible, stop the end and work it round as you did the water bend, but do not strike it too hard in one place, or you will find it give way and require to be dummied out again, or if you cannot get the dent out with the dummy send a ball through (see "Bending with Balls").

BENDING WITH BALLS OR BOBBINS.

This style of work is much practiced on small pipes, such as 2 in. to 3 in., especially by London plumbers. Method: Suppose your pipe to be 2 in., then you require your ball or bobbin about 1/16 in. less than the pipe, so that it will run through the pipe freely. Now pull the pipe round until it just begins to flatten, as at Fig. 37, put the ball into the pipe, and with some short pieces of wood (say, 2 in. long by 1½ in. diameter) force the ball through the dented part of the pipe, or you may use several different-sized balls, as at A B C, Fig. 40, and ram them through the pipe with a short mandrel, as at D M. You will require to proceed very carefully about this ramming, or otherwise you will most likely drive the bobbins through the back at L K J. You must also watch the throat part, G H I, to keep it from kinking or buckling-up; dress this part from the throat toward the back, in order to get rid of the surplus in the throat.

THREE-BALL OR LEAD DRIVING BALL AND DOUBLE-BALL BENDING.

Fig. 41 shows a method of bending with three balls, one of lead being used as a driver attached to a piece of twine. This is a country method, and very good, because the two balls are kept constantly to the work. First, put the two balls just where you require the bend, then pull the pipe slightly round; take the leaden ball and drop it on the ball, B, then turn the pipe the other end up and drop it on A, and do so until your bend is the required shape. You must be careful not to let your leaden ball touch the back of the pipe. Some use a piece of smaller leaden pipe run full of lead for the ball, C, and I do not think it at all a bad method, as you can get a much greater weight for giving the desired blow to your _boxwood_ balls.

BENDING WITH WINDLASS AND BRASS BALL.

This is an excellent method of bending small pipes. Fig. 42 will almost describe itself. A is a brass or gun metal ball having a copper or wire rope running through it, and pulled through the flattened part of the pipe as shown. It will be quite as well to tack the bend down to the bench, as at B, when pulling the ball through; well dress the lead from front to back to thicken the back. I have seen some plumbers put an extra thickness of lead on the back before beginning to bend. Notice: nearly all solid pressed pipes are thicker on one side than the other (as before remarked), always place the thickest part at the back.

HYDRAULIC OR CUP-LEATHER AND BALL BENDING.

Fig 43. This is my own method of pipe-bending, and is very useful when properly handled with plenty of force, but requires great care and practice. You must have a union sweated on the end, A, Fig. 43, and the ball, B, to fit the pipe. The cup-leather, E, should have a plate fixed on the front to press the ball forward. Pull up the pipe as you please, and pump the ball through; it will take all the dents out, and that too very quickly.

BENDING BY SPLITTING OR SPLIT-MADE BENDS.

This method of bending is much practiced in the provinces, and, for anything I know to the contrary, is one of the best methods in use, as by it you are likely to get a good substance of metal on the back of the bend whether the plumber be a good or a bad workman. Proceed as follows: Cut the pipe down the center to suit the length of your bend, as shown at A B, Fig. 44. It will be quite as well if you first set out this bend on the bench, then you may measure round the back, as from C to L, to obtain the distance of the cut, which should always be three or four inches longer than the bend. You may also in this way obtain the correct length for the throat, G H I; here you will see that you have a quantity of lead to spare, i.e., from A to E, all of which has to be got rid of in uncut bends--some plumbers shift from front to back, but how many? Not one in twenty. After you have cut the pipe, open the throat part, bend out the sides, and pull this part round a little at a time, then with a dummy, Fig. 38, work the internal part of the throat outward to as nearly the shape as you can. Go carefully to work, and do not attempt to work up the sides, A D B, until your throat is nearly to the proper shape, after which you may do so with a small boxwood dresser or bossing-stick (It is not necessary to explain minutely what a bosser or dressing-stick is, as they can be bought at almost any lead-merchants--the dresser is shown at E, Fig. 1; the bossing-stick is somewhat similar, the only difference being that it has a rounded face instead of flat.) Keep the dummy up against the sides when truing it. If you have proceeded properly with this throat part, you will not require to work up the sides or edges, as in working the throat back the sides will come up by themselves. Next take the back, pull it round a little at a time, the dummy being held inside, with your dresser work the two edges and sides slowly round, and the back will follow. Never strike the back from the underside with the dummy. After you have made a dozen or two you will be able to make them as fast as you please, but do not hurry them at first, as the greater part of this work is only to be learned by patient application, perseverance, and practice.