Chapter V: HYGIENE AND MEDICINE.--Parangi; a newly described (3)

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.

After you have made the bend it will require to be soldered, but before you can do this you must have the joint quite perfect and the edges true one with the other. A good bender will not require to touch his edges at all, but a novice will have to rasp and trim them up so that they come together. Having your edges true, soil them, take a gauge-hook, which may be described as a shave-hook with a gauge attached, and shave it about 1/8 in. each side; now solder it to look like the solder A, Fig. 45, which is done as follows: With some fine solder tack the joint at A D B, Fig. 44, put on some resin, and with a well-heated copper-bit drop some solder roughly on the point from B to A, then draw the bit over it again to float the solder, being especially careful not to let the joint open when coming off at A. Some plumbers think fit to begin here, but that is a matter of no importance. Do not forget that if your joint is not properly prepared, that is to say, true and even, it is sure to be a failure, and will have a "higgledy-piggledy" appearance. Some difference of opinion exists as to the best method of making these joints: one workman will make a good joint by drawing it while, on the other hand, another one will do it equally well by wiping it. Drawing will be fully explained in a part on pipe making. It may, however, be here mentioned that it is a method of making the joint by floating the solder along the joint with the ladle and plumbing-iron.

It is not uncommon for plumbers to make their bends with only one joint on the back.

PULLING UP BENDS.

In London, it is the favorite plan to make bends without cutting them. Fig. 46. It is done by taking a length of pipe, and, just where you require the bend, lay it (_with the seam at the side_) upon a pillow, made by tightly filling a sack with sand, wood shavings, or sawdust; have some shavings ready to hand and a good lath, also a short length of mandrel about 3 ft. long and about ½ in. smaller than the pipe, and a dummy as shown at A B, Fig. 56. Now, all being ready, put a few burning shavings into the throat of the bend, just to get heat enough to make it fizz, which you can judge by spitting on it. When this heat is acquired withdraw the fire, and let the laborer quickly place the end of the mandrel into the pipe, and pull the pipe up while you place a sack or anything else convenient across the throat of the bend, then pull the pipe up a little, just sufficient to dent it across the throat. Now, with a _hot_ dummy, dummy out the dent, until it is round like the other part of the pipe. Keep at this until your bend is made, occasionally turning the pipe or its side and giving it a sharp blow on the side with the soft or hornbeam dresser; this is when the sides run out as in Fig. 37. Never strike the back part of the bend from inside with the dummy, but work the lead from the throat to the back with a view to thickening the back.

SET-OFFS.

A set-off is nothing more than a double bend, as shown at Fig. 47, and made in much the same manner. D is the long end of the pipe. Always make this bend first and pull it up quite square, as it will be found to go a little back when pulling up the other bend; if you can make the two together so much the better, as you can then work the stuff from the throat of one bend into the back of the other. The different shaped dummies are also here shown: F a round-nosed dummy, G a double bent dummy, H a single bent, I straight, J hand-dummy, ABN a long bent dummy shown at Fig. 38.

BAD BENDS.

These can always be detected by examining them in their backs, as at Fig. 48; take a small dresser and tap the pipe a few times round ABD to test for the thickness. Strike it hard enough to just dent it; next strike the back part of the pipe, E, _with the same force_, and if it dents much more it is not an equally-made bend. I have seen some of these much-praised London-made bends that could be easily squeezed together by the pressure of the thumb and finger. N.B.--Care must be taken not to reduce or enlarge the size of the bore at the bend.

BAD FALLS IN BENDS.

The fall given in bending lead pipes should be considered of quite as much importance as making the bends of equal thickness especially for pipes, as shown in Fig. 49. In this Fig. you have a drawing of a bad bend. From A to B there is no fall whatever, as also from B to C; such bending is frequently done and fixed in and about London, which is not only more work for the plumber, but next to useless for soil-pipes. Fig. 50 shows how this bend should be made with a good fall from A to J, also from M to N; the method of making these bends requires no further explanation. R, P, and K are the turnpins for opening the ends, the method of which will be explained in a future paragraph on "Preparing for Fixing."

BENDS MADE INTO TRAPS OR RETARDERS.

It will sometimes be found requisite to retard the flow of water when running through soil or other pipes, or to direct it to another course, or even to form a trap in the length of pipe. This has been done in many ways, but Figs. 51 and 52 represent the method that I, after mature consideration, think most preferable. There is nothing new about this style of bending, as it has been long in vogue with provincial plumbers, but more especially in Kent. For many years it has had a run as a sink and slop closet-trap. Mr. Baldwin Latham, in his "Sanitary Engineering," says it was introduced and has been used for the Surrey and Kent sewers from about 1848.

I have also noticed many of these traps in the Sanitary Exhibition at South Kensington, made by Graham and Fleming, plumbers, who deserve a medal for their perseverance and skill, not only for the excellence of their bends, but also for some other branches of the trade, such as joint-wiping, etc., which is unquestionably the best work sent into this Exhibition--in fact, quite equal to that which was shown at the Exhibition of 1862. I shall treat further of these bends in an article on Fixing, in a future part.

BENDS MADE WITH THE "SNARLING DUMMY."

This is an American method of making lead bends. Fig. 53 shows a dummy made upon a bent steel rod, fixed into the bench. The method of working it is by first pulling up the bend, and to get out the dents, strike the rod of the snarling dummy, as shown at A, and the reaction gives a blow within the bend, throwing out the bend to any shape required. This method of working the dummy is also taken advantage of in working up embossed vases, etc.

_(To be continued)_

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THE GROSSENHAIN SHUTTLE-DRIVER.

The manufacture of fabrics having woofs of different colors requires the use of several shuttles and boxes containing the different colors at the extremity of the driver's travel, in which these boxes are adjusted alternately either by a rectilinear motion, or by a rotary one when the boxes are arranged upon a cylinder. The controlling mechanism of the shuttles by means of draught and tie machines constitutes, at present, the most perfect apparatus of this nature, because they allow of a choice of any shuttles whatever.

The apparatus constructed by the Grossenhainer Webstuhl und Maschinen Fabrik, of Grossenhain, and represented in the accompanying cut, is new as regards its general arrangement, although in its details it more or less resembles the analogous machines of Schönherr, Crompton, and Hartmann. The lifting of the shuttles is effected by two sectors, a1, a2, arranged on the two sides of the loom, and the rotary motion of which acts upon the box, c, by means of the lever, b, the box being caused to descend again by the spring, d. Parallel with the breast beam there is mounted an axle, e, and upon one of the extremities of this is fixed the sector, a1, while the other extremity carries two fixed disks, f1, f2, two loose disks, f3, f4, and the sector, a2, which is connected with the latter. The disks are kept in position by a brake, g. The pawls, h1 and h2, are supported on a lever, i, on a level with the disks, and are connected with the cam, l, by the spring, k. This cam revolves with the axle of the loom and thrusts the pawls against the disk. A draught and tie machine controls the action of the pawls on the disks in such a way that, by the revolution of the sectors, a1 and a2, the shuttle-boxes, I., II., III., are brought at the desired moment in the way of the driver. The pawls, h, are connected by wires with the bent levers, m, of the draught machine, which carry also the pawls, n. The upper position of the pawls, h, is limited by the direct resting of the levers, m, on the tappet, o, and the lower position by the resting of the pawls, n. The plates, p, held by the pattern, M, are set in motion horizontally by means of the eccentric, q, the crank, r, and the bent lever, s. The raised plates abut against the corresponding levers, m, and thus bring about the descent of the pawls, h, which are suspended from these levers. This position is maintained by the resting of the pawls, n, upon the tappet, o, until the lowering of the corresponding plate has set the pawl, n, free. The lever, m, then gives way to the action of the spring, t, and the pawl, h, rises again. The rotation of the cylinder which supports the design, M, is effected by the motion of the bent lever, s.

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INDUSTRIAL ART FOR WOMEN--CARPET DESIGNING.

A meeting of ladies was held in this city recently to consider the possibilities of industrial art in furnishing occupation for women.

Mrs. Florence E. Cory, Principal of the Woman's Institute of Technical Design, which was recently established in this city, advanced the proposition that whatever could be done by man in decorative art could be done as well by women, and she made an earnest plea to her own sex to fit themselves by proper training to engage in remunerative industrial work. Mrs. Cory enjoys the distinction of being the first woman who ever attempted to make designs for carpets in this country. She said that four years ago, when she came to this city, there was no school at which was taught any kind of design as applied to industrial purposes, except at Cooper Union, where design was taught theoretically but not practically. During the past year or two, however, in many branches of industrial design women have been pressing to the front, and last year eighteen ladies were graduated from the Boston Institute of Technology. Most of these ladies are now working as designers for various manufacturers, eight are in print factories, designing for chintz and calico, two have become designers for oil-cloths, one is designing for a carpet company, and one for a china factory. Carpet designing, said Mrs. Cory, is especially fitted for women's work. It opens a wide field to them that is light, pleasant, and remunerative. The demand for good carpet designs far exceeds the supply, and American manufactures are sending to Europe, particularly England and France, for hundreds of thousands of dollars' worth of designs yearly. If the same quality of designs could be made in this country the manufacturers would gladly patronize home talent. One carpet firm alone pays $100,000 a year for its designing department, and of this sum several thousands of dollars go to foreign markets. More technical knowledge is required for carpet designing than for any other industrial design. It is necessary to have a fair knowledge of the looms, runnings of color, and manner of weaving. Hitherto this knowledge has been very difficult, if not impossible, for women to obtain. But now there are a few places where competent instruction in this branch of industrial art is given.

There are several kinds of work connected with this business that may be done at home by those who wish, and at very fair prices. The price of copying an ingrain design is from $3 to $6 per sheet. The price for an original design of the same size is from $10 to $20. For Brussels or tapestry sketches, which may be made at home, provided they are as good as the average sketch, the artists receive from $15 to $30. For moquettes, Axminsters, and the higher grades of carpets some artists are paid as high as $200. The average price, however, is from $25 to $100. These designs may all be made at home, carried to the manufacturer, submitted to his judgment, and if approved, will be purchased. After the purchase, if the manufacturer desires the artist to put the design upon the lines and the artist chooses to do so, the work may still be done at home, and the pay will range from $20 to $75 extra for each design so finished. The average length of time for making a design is, for ingrains, two per week; Brussels sketch, three per week; Brussels on the lines, one in two weeks; moquettes and Axminsters, one in two or three weeks, depending of course upon the elaborateness and size of the pattern. When the work is done at the designing-rooms, and the artist is required to give his or her time from 9 o'clock in the morning until 5 in the afternoon, the salaries run about as follows: For a good original ingrain designer, from $2,000 to $3,000 per year. A good Brussels and tapestry designer from $1,500 to $6,000 per year. Copyists and shaders, from $3 to $10 per week.

Mrs. R.A. Morse advocated the establishment of schools of industrial art, in which there would be special departments so that young girls might be trained to follow some practical calling. Mrs. Dr. French said that unskilled labor and incompetent workmen were the bane and disgrace of this country, and she thought that the field of industrial art was very inviting to women. She disparaged the custom of decorating chinaware and little fancy articles, and said that if the time thus wasted by women was applied to the study of practical designing those who persevered in the latter branch of industrial art might earn liberal wages. Miss Requa, of the Public School Department, explained that elementary lessons in drawing were taught in the public schools. Mme. Roch, who is thoroughly familiar with industrial and high art in both this country and in Europe, said that if the American people would apply themselves more carefully to the study of designing they could easily produce as good work as came from abroad. The beauties to be seen in American nature alone surpassed anything that she had ever witnessed in the old countries.

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PHOTOGRAPHY UPON CANVAS.

One of the most extensive establishments for the purpose is that of Messrs. Winter, in Vienna. They say to photographers in general: If you will send us a portrait, either negative or positive, we will produce you an enlargement on canvas worked up in monochrome. The success of their undertaking lies in the circumstance that they do not produce colored work--or, at any rate, it is exceptional on their part to do so--but devote their efforts to the production of an artistic portrait in brown or sepia. In this way they can make full use of the dark brown photograph itself; there is less necessity for tampering with the enlarged image, and natural blemishes in the model itself maybe softened and modified, without interfering much with the true lines of face and features. The monotone enlargements of Messrs. Winter, again, exquisitely as most of them are finished, do not appear to provoke the opposition of the painter; they do not cross his path, and hence he is more willing to do them justice. Many a would-be purchaser has been frightened out of his intention to buy an enlargement by the scornful utterance of an artist friend about "painted photographs," and in these days of cheap club portraits there is certainly much risk of good work falling into disrepute. But a well-finished portrait in monotone disarms the painter, and he is willing to concede that the picture has merit.

"We cannot use English canvas, or 'shirting,' as you call it," said one of our hosts; "it seems to contain so much fatty matter." The German material, on the other hand, would appear to be fit for photography as soon as it had been thoroughly worked in hot water and rinsed. Here, in this apartment, paved with red brick, we see several pieces of canvas drying. It is a large room, very clean, here and there a washing trough, and in one corner two or three large horizontal baths. The appearance is that of a wash-house, except that all the assistants are men, and not washerwomen; there is plenty of water everywhere, and the floor is well drained to allow of its running off. We are to be favored with a sight of the whole process, and this is the first operation.

Into one of the horizontal baths, measuring about 5 by 4 feet, is put the salting solution. It is a bath that can be rocked, or inclined in any direction, for its center rests upon a ball-and-socket joint. It is of _papier mâché_, the inside covered with white enamel. Formerly, only bromine salts were employed, but now the following formula is adopted:

Bromide of potassium................... 3 parts. Iodide of potassium.................... 1 part. Bromide of cadmium..................... 1 " Water................................ 240 parts.

Four assistants are required in the operation, and the same number when it comes to sensitizing and developing, all of which processes are commenced in the same way. The bath is tilted so that the liquid collects at one end, and near this end two assistants hold across the bath a stout glass rod; then the canvas is dipped into the liquid, and drawn out by two other assistants over the glass rod. In this way the canvas is thoroughly saturated, and, at the same time, drained of superfluous liquid.

The canvas is hung up to dry; but as sometime must elapse before this particular piece will be ready for sensitizing, we proceed with another canvas which is fit and proper for that process. The room, we should have mentioned, is provided with windows of yellow glass; but as there is plenty of light nevertheless, the fact hardly strikes one on entering. The sensitizing, with a solution of nitrate of silver, is conducted with a glass rod in the same way as before, the solution being thus compounded:

Nitrate of silver........................ 4 parts. Citric acid.............................. 1 part. Water.................................. 140 parts.

Again the canvas is dried, and then comes its exposure.

This is done in a room adjoining. We lift a curtain and enter a space that reminds one of the underground regions of a theater. There are curtained partitions and wooden structures on every hand; dark murky corners combined with brilliant illumination. Messrs. Winter use the electric light for enlarging, a lamp of Siemens' driven by a six-horse power engine. The lamp is outside the enlarging room, and three large lenses, or condensers, on three sides of the light, permit the making of three enlargements at one end at the same time. (See Fig.)

The condenser collects the rays, and these shine into a camera arrangement in which the small negative is contained. The enlarged image is then projected, magic lantern fashion, upon the screen, to which is fastened the sensitized canvas. The screen in question is upon a tramway--there are three tramways and three screens in all, as shown in our sketch--and for this reason it is easy to advance and retire the canvas, for the purpose of properly focusing it.

Even with the electric light now employed, it is necessary to expose a considerable time to secure a vigorous impression. From ten minutes to half an hour is the usual period, determined by the assistant, whose experienced eye is the only guide. We should estimate the distance of the cameras from the enlarging apparatus to be about fourteen or fifteen feet in the instance we saw, and when the canvas was taken down, a distinct outline of the image was visible on its surface.

By the way, we ought to mention that the canvas is in a decidedly limp state during these operations. It has just sufficient stiffness to keep smooth on the screen, and that is all; the treatment it has received appears to have imparted no increase of substance to it. Again it is brought into the red-brick washing apartment, and again treated in one of the white enameled baths as before. This time it is the developer that is contained in the bath, and the small limp tablecloth--for that is what it looks like--after being drawn over the glass rod, is put back into the bath, and the developing solution rocked to and fro over it. The whiteness of the bath lining assists one in forming a judgment of the image as it now gradually develops and grows stronger. Here is the formula of the developer:

Pyrogallic acid......................... 10 parts. Citric acid............................. 45 " Water...................................410 "

The developer--which, it will be noted, is very acid--is warmed before it is used, say to a temperature of 30° to 40° C.; nevertheless, the development does not proceed very quickly. As we watched, exactly eight minutes elapsed before Mr. Winter cried out sharply, "That will do." Immediately one of the assistants seizes the wet canvas, crumples it up without more ado, as if it were dirty linen, and takes it off to a wooden washing trough, where it is kneaded and washed in true washerwoman fashion. Water in plenty is sluiced over it, and after more vigorous manipulation still, it is passed from trough to trough until deemed sufficiently free from soluble salts to tone. The toning--done in the ordinary way with gold--removes any unpleasant redness the picture possesses, and then follows the fixing operation in hyposulphite. As canvas is more permeable than paper, these two last processes are quickly got through.

The final washing of the canvas is very thorough. Again it is treated with all the vigor with which a good laundry-maid attacks dirty linen, the canvas, in the end, being consigned to a regular washing-machine, in which it is systematically worked for some time.

When the canvas picture at last is finished, it presents a very rough appearance, by reason of the tiny fibers that stand erect all over the surface. To lay these, and also to improve the surface generally, the canvas is waxed, the fabric is stretched, and a semi-fluid mass rubbed into it, heat being used in the process, which not only gives brilliancy, but seems also to impart transparency to the shadows of the picture. The result is a pleasant finish, without vulgar glare or glaze, the high lights remaining beautifully pure and white.

Of course, the price of these canvas enlargements varies with the amount of artistic work subsequently put upon them; but the usual charge made by Messrs. Winter for a well-finished life-size portrait, three quarter length, is sixty florins, or about £5 sterling as the exchange now stands. Besides working for photographers, Messrs. Winter are reproducing a large number of classic paintings and cartoons by photography on canvas in this way (some of them almost absolutely untouched), and these, as may be supposed, are finding a very large sale among dealers. Such copies must necessarily be of considerable value to artists and collectors, and altogether it would seem that Messrs. Winter have hit upon a novel undertaking, which bids fair to make them a handsome return for the outlay (large as it undoubtedly has been) made upon their Vienna establishment.--_Photo. News._

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DETECTION OF STARCH SUGAR SIRUP MIXED WITH SUGAR-HOUSE MOLASSES.[1]

[Footnote 1: A Paper read before the American Chemical Society,
September 2, 1881.]

BY P. CASAMAJOR.

In previous communications I have given processes for detecting the adulteration of cane-sugar by starch-sugar. The adulteration of sugar-house sirups by starch glucose is still more extensively practiced than that of sugar, and a great portion of sirups sold by retailers in this market is adulterated with starch glucose. This form of adulteration may be very easily detected by the use of strong methylic alcohol, in which the alcoholometer of Tralles or of Gay Lussac will indicate about 93½°.

A straight sugar-house sirup when mixed with three times its volume of this strong methylic alcohol will dissolve by stirring, giving a very slight turbidity, which remains suspended; while sirups containing the usual admixture of starch sugar give a very turbid liquid, which separates, when left at rest, into two layers, the lower being a thick viscous deposit containing the glucose sirup.

Considerable quantities are sold of a thin sirup, of about 32° Baumé, in which the proportion of sugar to the impurities is greater than in common sugar-house molasses. When a sirup of this kind is stirred with three times its volume of methylic alcohol, a marked turbidity and deposition will take place, which consists of pure sugar. The crystals are hard and gritty. They adhere to the sides of the glass, and are deposited on the bottom. There is no resemblance between this precipitate and that due to starch sugar sirup.

It may not be useless to mention that if a straight sugar-house sirup of about 40° B. density is stirred with three times its volume of _ethylic_ alcohol of about 93½° the sirup will not dissolve. Hence ethylic alcohol of this strength is not suitable for distinguishing a sirup mixed with starch glucose from a _straight_ sugar-house sirup.

The presence of starch glucose in sugar-house molasses may be easily detected by the optical saccharometer when the sirup has the usual density of about 40° B., and when starch sugar has been added in the usual quantities.

For making the test the usual weight should be taken (16.35 grammes for Duboscq's saccharometer, and 26.048 grammes for Ventzke's instrument). The direct test should show a percentage of sugar not higher than the number of Baumé degrees indicating the density, and it may be from 2 to 3 per cent. lower. To understand this, we must refer to the composition of cane-sugar molasses of 40° B.:

Sugar.......................................37.5 Insoluble impurities........................37.5 Water.......................................25

If the direct test should indicate 55 per cent. of sugar, and if the molasses were straight, the composition would be--

Sugar...........................................55 Soluble impurities..............................20 Water...........................................25

Now, a product of this composition would not be a clear sirup at 40° B., but a mixture of sirup and crystals. Therefore, if the product is a clear sirup at 40° B., and it tests 55 per cent., it cannot be _straight_.

The presence of starch glucose in sugar-house molasses may also be detected by the copper test. The possibility of applying this test, as well as those already indicated, rests on the fact that starch glucose is always added in very large quantities for the purposes of adulteration. A very small addition could not be satisfactorily detected.

The detection by the copper test rests on the observation that very nearly one-half of the soluble impurities in sugar-house molasses consists of glucose in the shape of inverted sugar. We have seen above that for a molasses of 40° B. the soluble impurities amount to about 37½ per cent. We may, then, lay down the rule: that the percentage of glucose shown by the copper test cannot, in a straight sugar-house molasses, be much greater than one-half of the number expressing the density in Baumé degrees. The reason is obvious from what has been said of the test by the optical saccharometer.

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FALSE VERMILION.--A curious case has been noticed in Germany, where a small cargo of vermilion was purchased, and, upon being analyzed, turned out to be red oxide of lead colored by eosine. This is an entirely novel sophistication. The eosine was separated from the oxide of lead by digesting the product for twenty-four hours in very strong alcohol. A much shorter time is sufficient to color the spirit enough to enable an expert chemist to detect the presence of this splendid organic coloring matter. Another kind of "vermilion" consists entirely of peroxide of iron, prepared especially to imitate the brilliant and costly sulphide of mercury, which it does very well, and is largely used in England, France, and America.

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THE POSITION OF MANGANESE IN MODERN INDUSTRY.

BY M.V. DESHAYES.

No body among the metals and the metalloids (silicium, titanium, tungsten, chromium, phosphorus, etc.) has occupied a more prominent position in modern metallurgy than _manganese_, and it is chiefly due to its great affinity for oxygen. When this substance was discovered, more than a century ago (1774), by the celebrated Swedish chemist and mineralogist, Gahn, by treating the black oxide of manganese in the crucible, no one would have thought that the new element, so delicate by itself, without any direct industrial use, would become, in the middle of the nineteenth century, one of the most powerful and necessary instruments for the success of the Bessemer process, as well for its deoxidizing properties as for the qualities which it imparts to steel, increasing its resistance, its durability, and its elasticity, as has been shown elsewhere.

Without entering into a complete history (for it is beyond the task which we have here assumed),[1] it will not be without interest to recall how, when manganese was first obtained in a pure state, that it was supposed that it would remain simply an object of curiosity in the laboratory; but when its presence was proved in spiegeleisen and when it came to be considered an essential ingredient in the best German and English works for cutlery steel (where it is thrown into the crucible as the peroxide), then we find that its qualities become better and better appreciated; and it is surprising that no technologist ever devoted his attention to the production of manganese alloys.

[Footnote 1: See _Engineering_, May 27, 1881]

It was not till after the investigations of Dr. Percy, Tamm, Prieger, and Bessemer, who employed crucibles for the production of these alloys, that Hendersen received the idea of utilizing it in the Siemens furnace. So important a compound could not remain unemployed. The works at Terre Noire produced, by the Martin furnace, for a number of years, ferro-manganese of 70 to 80 per cent. Shortly afterward, when competition in the market was established, the works at Carniola and at Carinthia, some English factories, and more especially the works at Saint-Louis, near Marseilles, of Terre Noire, of Montluçon, etc., successfully adopted the manufacture of _ferro-manganese with the blast furnace_, which is without doubt the method best adapted for the reduction of metallic oxides, as well in consideration of the reactions as from an economical point of view. Before very long it was possible to produce, by the blast furnace, alloys of 40, 60, 80, and even 86 per cent., in using the hot air apparatus of Siemens, Cowper, and Witwell, with the employment of good coke, and principally by calculating the charges for the fusion in such a manner as to obtain an extra basic and refractory slag.

Following in the same path, the Phoenix Co., of Ruhrort, sent, in 1880, to the Metallurgical Exposition of Dusseldorf, samples of ferro-manganese obtained in a blast furnace, with an extra basic slag in which the silica was almost entirely replaced by alumina. The works of L'Esperance, at Oberhausen, exhibited similar products, quite pure as to sulphur and phosphorus, and they had a double interest at the exhibition, in consideration of the agitation over the Thomas and Gilchrist process (see the discussions which were raised at the meeting of the Iron and Steel Institute). This process unfortunately requires for its prompt success the use of a very large quantity of spiegel or of ferro-manganese, in order to sufficiently carburize and deoxidize the burnt iron, which is the final product of the blowing.

The production of ferro-manganese by the blast furnace depends upon the following conditions.

1. A high temperature.

2. On a proper mixture of the iron ores and the manganese.

3. On the production of slag rich in bases.

These different conditions may be obtained with but slight variations at the different works, but the condition of a high temperature is one of the most important considerations, not only for the alloys of manganese, but equally as well for the alloys of iron, manganese, silicium, those of chromium, of tungsten, etc. It is also necessary to study the effects produced either in the crucible or in the blast furnace, and to examine the ores which for a long while have been regarded as not reducible.

The works of Terre Noire especially made at the same time, in the blast furnace, ferro-silicon with manganese, alloys which are daily becoming more important for the manufacture of steels tempered soft and half soft without blowing.

These alloys, rich in silicon, present the peculiarity of being poor in carbon, the amount of this latter element varying with the proportions of manganese. In addition to the alloys used in the iron and steel industry, we shall proceed to relate the recent progress obtained in the metallurgy of other materials (especially copper) by the use of _cupro-manganese_:

+---+---------+-------+---------+---------+------+------------------------------ | | Mn. | C. | Si. | S. | P. | | |per cent.| | | | | +---+---------+-------+---------+---------+------+ | A | 18 to 20| 2 to 3| 10 to 12| Traces | |Extra Quality for soft metals. | B | 15 to 18| 3.00 | 10 to 8 | scarcely|About |} Medium Quality | C | 15 to 10| 3.25 | 8 to 6 | percep- |0.100.|} | D | 5 to 10| 3.50 | 4 to 6 | tible. | |Ordinary for hard metals. +---+---------+-------+---------+---------+------+------------------------------

The first alloys of manganese and copper were made in 1848, by Von Gersdorff; soon after Prof. Schrötter of Vienna made compounds containing 18 or 20 per cent. of manganese by reducing in a crucible the oxides of copper and manganese mixed with wood charcoal and exposing to a high heat.

These alloys were quite ductile, very hard, very tenacious, and capable of receiving a beautiful polish; their color varies from white to rose color, according to the respective proportions of the two bodies; they are particularly interesting on account of the results which were obtained by adding them to certain metallic fusions.

It is well known that in the fining of copper by oxidation there is left in the fined metal the suboxide of copper, which must then be removed by the refining process, using carbon to reduce the copper to its metallic state. M. Manhès, taking advantage of the greater affinity of manganese for oxygen, found that if this last element was introduced into the bath of copper during the operation of refining, the copper suboxide would be reduced and the copper obtained in its metallic condition. For this purpose during these last years real cupro-manganese has been prepared, occupying the same position to copper as the spiegel or the ferro-manganese does toward the manufacture of steel. M. Manhès used these same alloys for the fusion of bronze and brass, and recommended the following proportions:

3 to 4 kilog. of cupro-manganese for 100 kilog. of bronze.
0.250 to 1 do. do. do. brass.
0.150 to 1.2 do. do. do. copper.

In every case the alloy is introduced at the moment of pouring, as is the case in the Bessemer or Martin process, taking care to cover the fusion with charcoal in order to prevent the contact with air, together with the use of some kind of a flux to aid in the scorification of the manganese.

According to M. Manhès a slight proportion of manganese added to bronze appears to increase its resistance and its ductility, as is shown in the following table, provided, however, that these different alloys have been subjected to the same operations from a physical point of view; that is, pouring, rolling, etc.

--------------------------+-----+-----+------+----------+------------+ | | | | Weight | | | Cu. | Sn. | Mn. | of | Elongation | | | | | fracture | | --------------------------+-----+-----+------+----------+------------+ Ordinary Bronze | 90 | 10 | | 20 kil. | 4.00 | Bronze with Manganese, A, | 90 | 10 | 0.5 | 24 " | 15.00 | Do. do. B, | 90 | 10 | 1.0 | 26 " | 20.00 | --------------------------+-----+-----+------+----------+------------+

The White Brass Co., of London, exhibited at Paris, in 1878, manganese bronzes of four grades of durability, destined for different uses and corresponding to about 20 to 25 kilos of the limit of elasticity, and 36 to 37 kilos of resistance to fracture; the number 0 is equivalent after rolling to a resistance to fracture of 46.5 kilos, and 20 to 25 per cent. of elongation.

Such results show beyond contradiction the great interest there is in economically producing alloys of copper, manganese, tin, zinc, etc. In addition, they may be added to metallic fusions, for deoxidizing and also to communicate to the commercial alloys (such as bronze, brass, etc.) the greatest degree of resistance and tenacity.

While many investigators have tried to form alloys of copper and manganese by combining them in the metallic state (that is to say, by the simultaneous reduction of their oxides), the Hensler Bros., of Dillenburg, have found it best to first prepare the _metallic manganese_ and then to alloy it in proper proportions with other metals. Their method consisted of reducing the pure pyrolusite in large plumbago crucibles, in the presence of carbon and an extra basic flux; the operation was carried on in a strong coke fire, and at the end of about six hours the _crude manganese_ is poured out, having the following composition:

Manganese 90 to 92
Carbon 6 to 6.5
Iron 0.5 to 1.5
Silicon 0.5 to 1.2

By refining, the manganese can be brought up to 94 to 95 per cent. of purity. It is from this casting of pure manganese that is obtained the substance used as a base for the alloys. This metal is white, crystalline, when exposed to the damp air slowly oxidizes, and readily combines with copper to form the _cupro-manganese_ of the variety having the composition--

Copper 70
Manganese 30

Cast in ingots or in pigs it becomes an article of commerce which may be introduced in previously determined proportions into bronze, gun metal, bell metal, brass, etc. It may also be used, as we have already mentioned, for the refining of copper according to Manhès's process.

Tests made from this standpoint at the works of Mansfield have shown that the addition of 0.45 per cent. of cupro-manganese is sufficient to give tenacity to the copper, which, thus treated, will not contain more than 0.005 to 0.022 of oxygen, the excess passing off with the manganese into the scorias.

On the other hand, the addition of cupro-manganese is recommended, when it is desirable to cast thin pieces of the metal, such as tubes, caldrons, kitchen utensils, which formerly could only be obtained by beating and stamping.

The tenacity obtained for tubes of only three centimeters in diameter and 1.75 millimeters in thickness is such that they are able to withstand a pressure of 1,100 pounds to the square inch.

The _manganese bronze_, which we have previously referred to, and which is used by the White Brass Company of London, is an alloy of copper, with from one to ten per cent. of manganese; the highest qualities of resistance, ductility, tenacity, and durability are obtained with one to four per cent. of manganese, while with twelve per cent. the metal becomes too weak for industrial uses.

+-----------+---------+-----------+-------------+------------+
| Manganese | | | Weight of | |
| bronze. | Copper.| Manganese.| fracture in | Elongation.|
| | | | kilos per | |
| | | | square mm. | |
+-----------+---------+-----------+-------------+------------+
| A | 96.00 | 4.00 | 19.00 | 14.60 |
| B | 95.00 | 5.00 | 20.62 | 10.00 |
| C | 94.00 | 6.00 | 20.80 | 14.60 |
| D | 90.00 | 10.00 | 16.56 | 5.00 |
+-----------+---------+-----------+-------------+------------+

The preceding table gives some of the experimental results obtained with the testing machine at Friedrich-Wilhelmshütte on the crude cast ingots; the resistance is increased, as with copper, by rolling or hammering.

The _manganese German silver_ consists of

Copper................ 70.00
Manganese............. 15.00
Zinc.................. 15.00

But as this alloy often breaks in rolling, the preference is given to the following proportions:

Copper................ 80.00
Manganese............. 15.00
Zinc.................. 5.00

This results in a white, ductile metal, which is easily worked and susceptible of receiving a beautiful polish, like the alloys of nickel, which it may in time completely replace.

The _bronzes of manganese, tin, and zinc_ were perhaps the first upon which important investigations were made; they were obtained by adding to an alloy of copper, zinc, and tin (ordinary bronze) a definite quantity of the cupro-manganese of the type indicated above (Cu 70, Mn 30). By this means the resistance is increased fully nine per cent., probably in the same way as the copper, that is, by the deoxidizing effect of the manganese, as both the copper and the tin are always more or less oxidized in ordinary bronzes.

Manganese combines with tin just the same as it does with copper, and the proportion which is recommended as giving the highest resistances is three to six per cent. of cupro-manganese.

However, notwithstanding the use of cupro-manganese, the tin, as in ordinary bronzes, has a tendency to liquate in those portions of the mould which are the hottest, and which become solid the last, especially in the case of moulds having a great width.

From a series of experiments made at Isabelle Hütte, it has been found that the metal which has the greatest resisting qualities was obtained from

Copper......................85.00
Manganese................... 6.00
Zinc........................ 5.00

5 per cent. of cupro-manganese = manganese 1.00 remaining in the metal.

The best method of procedure is first to melt the copper in a crucible, and then to add the tin and the zinc; finally the cupro-manganese is added just at the moment of pouring, as in the Manhès process; then the reaction on the oxides is very effective, there is a boiling with scintillation similar to the action produced in the Bessemer and Martin process when ferro-manganese is added to the bath of steel.

The following are some of the results obtained from thirteen alloys obtained in this manner. These samples were taken direct from the casting and were tested with the machine at Friedrich-Wilhelms-hütte, and with the one at the shops of the Rhine Railroad. Their resistance was considerably increased, as with the other alloys, by rolling or hammering.

-------+------+------+-----+---------+---------+----------+--------+-------+
| | | | | | | Weight | |
| | | | | |Limit of | of | Elong-|
|Nature| | | | |elasticity|fracture| ation,|
| of | | | | Cupro- |in kilos |in kilos| per- |
Numbers|mould.|Copper| Tin.| Zinc. |manganese|per mm. | per mm.|centage|
-------+------+------+-----+---------+---------+----------+--------+-------+
1 | Sand | 85.00| 6.00| 5.00 | | 11.30 | 16.00 | -- |
2 | -- | 85.00| 6.00| 5.00 | 4.00 | 13.00 | 16.10 | 2.00 |
3 | Cast.| 87.00| 8.70| 4.30 | 4.00 | -- | 19.40 | -- |
4 | -- | 85.00| 6.90| 5.00 | 6.00 | -- | 18.80 | 6.00 |
5 | -- | 85.00| 6.00| 5.00 | 6.00 | -- | 19.75 | 7.00 |
6 | -- | 85.00| 6.00| 5.00 | 10.00 | -- | 17.15 | 4.00 |
7 | Sand | 87.00| 5.20| 4.33 | 3.47 | -- | 19.70 | 8.70 |
8 | -- | 87.00| 5.20| 4.33 | 3.47 | -- | 19.70 | 8.90 |
9 | -- | 85.00| 6.00| 5.00 | 3.00 | 16.80 | 22.00 | -- |
10 | -- | 74.00|10.00| 5.00 | 3.30 | 13.80 | 18.70 | -- |
| | | |(7.66 Pb)| | | | |
11 | -- | 78.70| 8.00| ( 8 Pb) | 3.30 | 13.80 | 20.70 | -- |
12 | -- | 82.00| 9.80| 4.90 | 3.30 | 14.75 | 19.75 | -- |
13 | -- | 86.20|16.50| -- | 3.30 | 14.30 | 24.70 | -- |
-------+------+------+-----+---------+---------+----------+--------+-------+

The results of the tests of ductility which are here given, with reference to the _cupro-manganese_, _manganese bronze_, the _alloys_ with _zinc_ and _tin_, are taken from M.C. Hensler's very valuable communication to the Berlin Society for the Advancement of the Industrial Arts.

These various alloys, as well as the _phosphorus bronze_, of which we make no mention here, are at present very largely used in the manufacture of technical machines, as well as for supports, valves, stuffing-boxes, screws, bolts, etc., which require the properties of resistance and durability. They vastly surpass in these qualities the brass and like compounds which have been used hitherto for these purposes.--_Bull. Soc. Chim., Paris_, xxxvi. p. 184.

* * * * *

THE ECONOMICAL WASHING OF COAL GAS AND SMOKE.