Chapter 9

It may be out of place to digress a moment to illustrate the moral effect of such a convulsion. Several weeks after this great mine explosion, the 18th Army Corps, to which I then belonged, was holding a line of works recently captured from the rebels, about six miles from Richmond, when one night the colonel commanding Fort Harrison, a large field work forming a part of this line, came down to headquarters and reported that some old Pennsylvania coal miners in his command had heard mining going on under the fort. As the nearest part of the enemy's line was some 400 yards from the fort, I was quite certain that they could not have run a gallery that distance in the time that had elapsed since we occupied the work, but there was of course the possibility that the mine had been partly built beforehand so as to be ready in just such a case as had arisen, viz., the capture of the fort by our troops. I therefore went with the colonel up to the fort to listen for the mining operations, and got the men who claimed to have heard the subterranean noises, down in the bottom of the ditch of the fort, which was ten feet deep, and at the angles formed a fairly good listening gallery, but nothing unusual could be heard. I therefore made arrangements to sink a line of pits in the bottom of the ditch, something like ordinary wells; the bottoms of these pits to be finally connected by a horizontal gallery which would envelop the fort and enable us to hear the enemy and blow him up, before he could get under the fort. Although the commanding officer of that fort was as brave an officer as the war developed, he would not keep his men in the fort after dark, but withdrew them quietly to the flanks of the work, where they not only would be safe from an explosion, but would be ready to fall upon the enemy in case he should blow up the fort and rush in to capture the line, as our troops had attempted to do at Petersburg. No explosion took place, however, and after our countermining work was completed, the garrison became reassured and remained in the fort at night as well as in day time. A few months later, when the enemy was driven from his lines, I went through his works to see whether any mining had been attempted, and found that a gallery leading toward Fort Harrison had been carried quite a distance, but was still incomplete, and it is barely possible that the old miners were right, after all, in thinking that they could hear the sound of the pick, although the distance was almost too great to make this theory very probable.

Still another illustration of the way in which civil engineers can make themselves extremely useful in military operations was the wonderful system of military railways, or railways operated for military purposes, that formed complete lines of transportation for the armies and their enormous quantities of supplies and munitions, more especially those in the West and Southwest. Construction trains were organized in the most complete style, and when a piece of track or a number of bridges were destroyed by the enemy, they would be rebuilt so rapidly that our trains would hardly seem to be delayed by it. The trains carried spare rails, ties, and bridges of various lengths ready to put up, and they also carried the necessary rolling stock and tools for destroying the roads and bridges of the enemy. So expert had this construction corps become that the enemy was ready to believe almost any statement in regard to it. General Sherman tells of an instance where it was proposed to blow up a tunnel, to check his "March to the Sea," when one of the men objected, saying it was of no use, for Sherman had a duplicate tunnel in his train.

Although this is not a sermon, it may not be out of place to point out a few qualifications common to all engineers, for they all deal more or less with the same materials and forces and employ similar methods of investigation and construction. Wood, iron, steel, copper and stone and their compounds are the materials of the civil, mining, mechanical and electrical, as well as of the military engineers. They all deal with the forces of gravitation, cohesion, inertia and chemical affinity. They all require skill, intelligence, industry, confidence, accuracy, thoroughness, ingenuity and, beyond all, sound judgment. Wanting in any one of these qualifications, an engineer is more or less disqualified for important work. It is said that a distinguished engineer was always afraid to cross his own bridges, although built in the most thorough and approved manner. He was deficient in confidence. Another engineer distinguished for his mathematical attainments built a bridge which promptly collapsed at the first opportunity. On overhauling his computations he ejaculated somewhat forcibly, "That confounded minus sign! It should have been plus." He was deficient in sound judgment, or what is sometimes called "horse sense."

Another and more common defect in young engineers is a want of thoroughness. It is generally best to go to the bottom of a question at first and keep at it until it is thoroughly and fully completed. Confucius says, "If thou hast aught to do, first consider, second act, third let the soul resume her tranquillity." Those who begin a great many things and never fully complete them lose a great deal of valuable time, but do very little valuable work. The way to avoid this difficulty is to be cautious about beginning things, but when once started don't leave it until you are satisfied to leave it for good. There is an Arabian saying, "Never undertake _all_ you can do, for he who undertakes _all_ he can do will frequently undertake _more_ than he can do."

Another common error is extravagance. On the plea that "the best is always the cheapest," and to be sure of a large factor of safety, or as the late Mr. Holley called it a "factor of ignorance," without much trouble to themselves, some engineers use more or better materials than the work requires, and thus greatly increase the cost without any corresponding advantage. Almost any engineer can do almost anything in the way of engineering if not limited by the cost, but the man who knows just what materials to use and how to use them so that they will answer the purpose as to strength and durability can save his own salary to his employer many times over by simply omitting unnecessary expense.

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HOW MECHANICAL RUBBER GOODS ARE MADE.

While the manufacture of rubber goods is in no sense a secret industry, the majority of buyers and users of such goods have never stepped inside of a rubber mill, and many have very crude ideas as to how the goods are made up. In ordinary garden hose, for instance, the process is as follows: The inner tubing is made of a strip of rubber fifty feet in length, which is laid on a long zinc-covered table and its edges drawn together over a hose pole. The cover, which is of what is called "friction," that is cloth with rubber forced through its meshes, comes to the hose maker in strips, cut on the bias, which are wound around the outside of the tube and adhere tightly to it. The hose pole is then put in something like a fifty foot lathe, and while the pole revolves slowly, it is tightly wrapped with strips of cloth, in order that it may not get out of shape while undergoing the process of vulcanizing. When a number of these hose poles have been covered in this way they are laid in a pan set on trucks and are then run into a long boiler, shut in, and live steam is turned on. When the goods are cured steam is blown off, the vulcanizer opened and the cloths are removed. The hose is then slipped off the pole by forcing air from a compressor between the rubber and the hose pole. This, of course, is what is known as hose that has a seam in it.

For seamless hose the tube is made in a tubing machine and slipped upon the hose pole by reversing the process that is used in removing hose by air compression. In other words, a knot is tied in one end of the fifty foot tube and the other end is placed against the hose pole and being carefully inflated with air it is slipped on without the least trouble. For various kinds of hose the processes vary, and there are machines for winding with wire and intricate processes for the heavy grades of suction hose, etc. For steam hose, brewers', and acid hose, special resisting compounds are used, that as a rule are the secrets of the various manufacturers. Cotton hose is woven through machines expressly designed for that purpose, and afterward has a half-cured rubber tube drawn through it. One end is then securely stopped up and the other end forced on a cone through which steam is introduced to the inside of the hose, forcing the rubber against the cotton cover, finishing the cure and fixing it firmly in its place.

CORRUGATED MATTING.

After the mixing of the compound and the calendering, that is the spreading it in sheets, the great roll of rubber and cloth that is to be made into corrugated matting is sent to the pressman. Here it is hung in a rack and fifteen or twenty feet of it drawn between the plates of the huge hydraulic steam press. The bottom plate of this press is grooved its whole length, so that when the upper platen is let down the plain sheet of rubber is forced into the grooves and the corrugations are formed. While in that position steam is let into the upper and lower platens and the matting is cured. After it has been in there the proper time, cold water is let into the press, it is cooled off, and the upper platen being raised, it is ready to come out. A simple device for loosening the matting from the grooves into which it has been forced is a long steel rod, with a handle on one hand like an auger handle, which, being introduced under the edge and twisted, allows the air to enter with it and releases it from the mould.

PACKING.

Sheet packing is often times made in a press, like corrugated matting. The varieties, however, known as gum core have to go through a different process. Usually a core is squirted through a tube machine and the outside covering of jute or cotton, or whatever the fabric may be, is put on by a braider or is wrapped about it somewhat after the manner of the old fashioned cloth-wrapped tubing. The fabric is either treated with some heat-resisting mixture or something that is a lubricant, plumbago and oil being the compound. Other packings are made from the ends of belts cut out in a circular form and treated with a lubricant. There are scores of styles that make special claims for excellences that are made in a variety of ways, but as a rule the general system as outlined above is followed.

JAR RINGS.

The old fashioned way of making jar rings was first to take a large mandrel and wrap it around with a sheet of compounded rubber until the thickness of the ring was secured. It was then held in place by a further wrapping of cloth, vulcanized, put in a lathe and cut up into rings by hand. That manner of procedure, however, was too slow, and it is to-day done almost wholly by machinery. For example, the rubber is squirted out of a mammoth tubing machine in the shape of a huge tube, then slipped on a mandrel and vulcanized. It is then put in an automatic lathe and revolving swiftly is brought against a sharp knife blade which cuts ring after ring until the whole is consumed, without any handling or watching.--_India Rubber World_.

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HOW ENAMELED LETTERS ARE MADE.

The following is a description of a brief visit by a representative of the _Journal of Decorative Art_ to the new factory of the Patent Letter and Enamel Company, Ltd., situate in the East End of London.

The company have recently secured a large freehold plot in the center of the East End of London, and have built for themselves a most commodious and spacious factory, some hundreds of feet in length, all on one floor, and commanded from one end by the manager's office, from whence can be seen at a glance the entire premises.

The works are divided into two large compartments, and are lighted from the roof, ample provision being made for ventilation, and attention being given to those sanitary conditions which are, or should be, imperative on all well managed establishments.

We first explore the stockroom. Here are stored the numerous dies, of all sizes and shapes, which the company possess, varying in size from half an inch to twelve or sixteen inches. Here, too, is kept the large store of thin sheet copper out of which the letters are stamped. Our readers are familiar with the form or principle upon which these letters are made. It is simply a convex surface, the reverse side being concave, and being fixed on to the glass or other material with a white lead preparation. When these letters were first made, the practice was to cut or stamp them out in flat copper, and then to round or mould them by a second operation. Recent improvements in the machinery, however, have dispensed with this dual process, and the stamping and moulding is done in the one swift, sharp operation.

The process of making an enameled letter has four stages--stamping, enameling, firing, and filing. There are other and subsequent processes for elaborating, but those named are of the essence of the transaction.

STAMPING.

The stamping is done by means of presses, and is a very rapid and complete operation.

The operator takes a piece of the sheet copper, places it on the press, the lever descends, there is a sharp crunching, bursting sound, and in a time shorter than it has taken to describe, the letter is made, sharp and perfect in every way.

ENAMELING.

The letters are now taken charge of by a girl, who lays them out on a wire tray, the hollow side up, and paints them over with a thin mordant. While they are in this position, and before the mordant dries, they are taken on the gridiron-like tray to a kind of large box, which is full of the powdered enamel, and, holding the tray in her left hand, the girl takes a fine sieve full of the powder and dusts it over the letter, all superfluous powder falling through the open wirework and into the bin again, so that there is absolutely no waste.

FIRING.

The letters are now taken and placed carefully on thin iron disks or plates on the bench, where they remain until they are fired. It will be remembered that we said at the outset that the factory was divided into two large compartments, and it is into the second of these that we now go.

Here are ranged the series of furnaces which convert the copper and superincumbent enamel into one common body--fuse the one into the other. An unwary step soon warns us that we are too near the furnace, unless we want to run the risk of a premature cremation, and in the interests of the readers of this journal we step back to a respectful and proper distance, and watch the operations from afar.

There seems to be something innately picturesque about all furnaces and those who work about them. Whether it is the Rembrandt effects produced by the strong light and shade, or whether it is that the necessary use of the long iron instruments, such as all furnace workers employ, compels a certain dignity and grace of poise and action, we know not; but certain it is that the grace is there in a marked degree, and as we watched the men take their long-handled iron tongs and place in or lift out the plates of hot metal, we could not fail to be impressed with the charm of the physical action they displayed.

The disk containing the enameled letters is taken at the end of a long iron handle and carefully placed in a dome-shaped muffle. These muffles are all heated from the outside; that is, the fire is all round the chamber, but not in it, the fumes of the sulphur being destructive of the enamel if they are allowed to come into contact with it. So intense is the heat, however, that a muffle lasts only about nine days, and at the end of that time has to be renewed.

After the enamel is fused on to the copper, the disk is taken out and placed on a side slab, where it is allowed to cool.

This process is repeated on the front side of the letter, when all that remains to complete it is

THE FILING.

This is done by girls, who, with very fine files, rub off the edges and any protuberances which may be there. Every letter is subject to this operation, and all are turned out smooth and well finished.

Sometimes the letters are colored or further defined by the addition of a line, but the essentials are as we have already described.

BRUSHING OUT.

There are, however, one or two other operations of interest which we may notice. The company do not confine their exertions to the making of letters, various collateral developments having taken place which fill an important part in this scheme of work.

Of these, small tablets, containing advertisements or notices, such as we see in railway carriages, "Push after raising window," or "Close this door after you," or some legend pertaining to Brown's Soap or Robinson's Washing Powder. These are done by different processes, the transfer process, as used in the potteries, being employed, but the one most largely used is that of "brushing out," which is done by plates.

Let us suppose that the tablet shows white letters on a dark ground, the _modus operandi_ is as follows:

The tablet has been enameled, as already described, and is white. The operator now takes a dark enamel and spreads it evenly over the entire surface of the tablet. He, or she, now takes a stencil plate, of tinfoil, out of which the ground is cut, leaving the letter in the center.

This is carefully placed over the tablet and held tight with the left hand, while with the right hand he holds a fine brush, which he uses with a quick, sharp movement over the surface. This action readily removes the unfired color from the hard, glassy surface underneath, and leaves a white letter. This is fired, and is then complete.

Sometimes two and, it may be, three plates are necessary to complete the brushing out, as ties must be left, as in the case of ordinary stencils, and these have to be brushed out with additional plates. Two or three colors may be introduced by this process, but each separate color means separate firing. If the letters are dark on a light ground, the process is exactly the same, the stencil only being modified. In addition to the letters and tablets thus described, the company also undertake the production of large enameled signs, and to cope with the rapid expansion of this department of their work they are erecting special furnaces, to enable them to deal with any demand likely to be made upon them. The call for things permanent and washable in the way of advertising is on the increase, and the enameled plates made by the company is one of the most successful ways of meeting the demand.

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BURNING BRICK WITH CRUDE OIL FUEL.

At the present time there is not the least reason why either wood, coal, or any other solid fuel should be used for the burning of brick. This style of burning brick belongs to a past age. The art of brickmaking has made tremendous progress during the past quarter of a century. It is no longer the art of the ignorant; brains, capital, experience, science, wide and general knowledge, must in these days be the property of the successful brick manufacturer. There are some such progressive brick manufacturers in Chicago, who use neither coal nor wood in the drying or burning of their clay products. Crude oil is the fuel which they employ, and with this fuel they obtain cheaper and better brick than do manufacturers who employ solid fuel. Some of these manufacturers have expressed themselves as preferring to quit the brick business rather than return to the use of wood or coal as fuel in brick burning.

This shows plainly that progress in our art, when it does come, comes to remain. It is true that crude oil for brick-burning purposes is not everywhere obtainable. But there is a fuel which is even better than crude oil, namely, fuel gas, and which can be produced and employed on any brick yard at a saving of seventy-five per cent. over coal or other solid fuel.

The Rose process for making fuel gas gives a water gas enriched by petroleum. Roughly, about half the cost of this gas as made at Bellefonte, Pa., was for oil. The gas cost 6.68c. per 1,000 cu. ft., with oil at 2¼c. a gallon. At double this price the gas would cost but 10c., and show that in practice, foot for foot, it equals natural gas.

Fuel gas means a larger investment of capital than does any of the other modes of brick burning, and is, therefore, not within the reach of the entire trade. The cost of appliances for burning brick with crude oil is not very large, and as all grate bars, iron frames, and doors can be dispensed with in the use of crude oil fuel, the cost of an oil-burning equipment is but little in excess of an equipment of grates, etc., for coal-burning kilns.

At works using small amounts of fuel, especially if cost of fuel bears but a small proportion to total cost of the manufactured product, oil will be in the future very largely used. It is clean, as compared with coal, can be easily handled, and when carefully used in small quantities, is safe. There are several methods of burning oil that are well adapted to the use of brick manufacturers and other fuel consumers.

The Pennsylvania Railroad made some very thorough experiments on the use of petroleum in their locomotives, and while the results obtained are reported to have been satisfactory, it was the opinion of those having the experiments in charge that the demand for the Pennsylvania Railroad alone, were it to change its locomotives from coal to oil, would consume all the surplus and send up the price of oil to a figure that would compel a return to coal.

It is true that production has enormously increased in the last three years, and the promise for the near future is that a high rate will be maintained. It is further true that the production of Russia has increased enormously, and will probably be larger this year than ever before. This Russian oil must go to markets and supply demands that have been met by American oil, and this will still further increase the amount of oil available for fuel purposes.

There is no doubt, therefore, that petroleum has a future for fuel uses. Many brick manufacturers are ready to use it, notwithstanding the possibility of an advance in its cost.

While there are some objections to the use of petroleum as a fuel, growing chiefly out of the risk attending its storage and conveyance to the point of consumption, it is undoubtedly true that the chief objection is the fear that with the increased demand that would follow any extended use for this purpose would come an increase in price that would make its continued use too expensive.

Just four years ago, when the fuel oil industry was first projected, it was cried down because, as its enemies claimed, there was not enough oil fuel to be obtained in America to supply the New York City factories alone, to say nothing of other territory, and because of the high prices for oil that were sure to follow its substitution for coal fuel. Since then the industry has experienced a magnificent success, the sales exceeding 20,000,000 barrels a year, while the price is lower than ever.