1.Pepsin (pure)128grains.Dilute muriatic acid5drops.Simple elixir3fl. ounces.Glycerin1"Water16"Angelica wine6"Dissolve by agitation and filter through purified talcum.2.Glycerole of pepsin3parts.Sherry wine5"Glycerin1"Simple elixir, to make16"3.Pepsin in scales64grains.Glycerin1fl. ounce.Elixir taraxacum compound1"Alcohol2"Oil of cloves1drop.Sirup2fl. ounces.Dilute hydrochloric acid1fl. drachm.Water, to make16fl. ounces.
—Pharmaceutical Era.
Applications to Insect Bites.—Brocq and Jacquet (Indépendance médicale, October 20) recommend the following for the bites of bugs, fleas and gnats:
1.Camphorated oil of chamomile100parts.Liquid storax20"Essence of peppermint5"M.2.Olive oil20parts.Storax ointment25"Balsam of Peru5"M.3.Naphthol5 to 10 parts.Ether, enough to dissolve it.Menthol¼ to 1 part.Vaseline100 parts.
Bead for Liquors.—In the liquor trade, anything added to liquors to cause them to carry a "bead" and to hang in pearly drops about the side of the glass or bottle when poured out or shaken is called "beading," the popular notion being that liquor is strong in alcohol in proportion as it "beads." The object of adding a so-called "bead oil" is to impart this quality to a low-proof liquor, so that it may appear to the eye to be of the proper strength. The following formulas for "bead oil" are given:
1.Sweet almond oil1fl. ounce.Sulphuric acid, concentrated1"Sugar, lump, crushed1ounce.Alcohol, sufficient.
Triturate the oil and acid very carefully together in a glass, Wedgwood or porcelain mortar or other suitable vessel; add by degrees the sugar, continue trituration until the mixture becomes pasty, and then gradually add enough alcohol to render the whole perfectly fluid. Transfer to a quart bottle and wash out the mortar twice or oftener with strong alcohol until about 20 fluid ounces in all of the latter has been used, the washings to be added to the mixture in the bottle. Cautiously agitate the bottle, loosely corked, until admixture appears complete, and set aside in a cool place. This quantity of "oil" is supposed to be sufficient for 100 gallons of liquor, but is more commonly used for about 80 or 85 gallons. The liquor treated with this "oil" is usually allowed to become clearer by simple repose.
2.Soapwort, coarsely ground13ounces.Diluted alcohol, enough to make1gallon.
Extract the soapwort by maceration or percolation.
This is also intended for 80 gallons of liquor, preferably adding to the latter one-half gallon of simple sirup.
The ingredients of the above formulas, according to the "Manual of Beverages," are not injurious—not at least in the quantities required for "beading." It is said that beyond a certain degree of dilution of the liquor with water, these preparations fail to produce the intended effect. The addition of sugar or sirup increases their efficacy.—Pharmaceutical Era.
Quinine Hair Tonic.—
1.Quinine sulphate1part.Tincture cantharides10"Glycerin75"Alcohol500"Tincture rhatany20"Spirit lavender50"2.Tincture cinchona50"Tincture cantharides25"Peru balsam20"Tincture soap150"Cologne water250"Cognac2,000"Oil bergamot10"Oil sweet orange10"Oil rose geranium3"3.Bisulphate of quinine½ounce.Vinegar of cantharides2½"Spirit of rosemary18"Lavender water8"Glycerite of borax1"Glycerin14"Distilled water80"Caramel, sufficient to color.
—Pharmaceutical Era.
Soap for Removing Rust.—
Parts by Weight.Whiting9Oil soap6Cyanide of potassium5Water60
Dissolve the soap in water over the fire and add the cyanide, then little by little the whiting. If the compound is too thick, which may be due either to the whiting or the soap employed, add a little water until a paste is made which can be run into an iron or wooden mould. This will remove rust from steel and give it a good polish.—Oils, Colors and Drysalteries.
Messrs A. & J. Inglis, shipbuilders and engineers, of Pointhouse, Glasgow, have recently built a somewhat unique and certainly interesting steamer, for the conveyance of passengers between Port an Basque, in Newfoundland, and Sydney, Cape Breton, in connection with the Newfoundland and Canadian systems of railways. The distance from port to port is about one hundred miles, and the vessel has been designed to make the run in six hours. Messrs. Reid, of Newfoundland, who have founded the line of steamers to perform this service, intrusted to Messrs. Inglis the task of producing a vessel in all respects suitable for the work to be accomplished. The steamer "Bruce," the pioneer steamer, an illustration of which we are enabled to produce, is the result. The navigation of the waters in which this vessel will be employed is attended with some difficulties. Not only are storms of frequent occurrence, but in the months of winter and spring large quantities of drift ice are commonly encountered.
To obtain the necessary speed and carry all that was required on a suitable draught of water, it was essential that the "Bruce" should be built of steel, but in view of the severe structural and local stresses to which she must inevitably be subjected when at sea, it was necessary to afford adequate stiffening and means for preventing penetration or abrasion by ice. Hence the frames are more closely spaced than is usual in vessels of her size, numerous web frames associated with arched supports at the main deck and adjacent to the waterline are fitted throughout her entire length, and a belt of 3-inch greenheart planking, with a steel sheathing over it at the fore part of the vessel, is further provided. Indeed, throughout the vessel, every precaution has been taken with a view to insure her efficiency and safety when running swiftly from port to port, while at the same time the materials employed have been most wisely, judiciously and economically distributed.
THE NEWFOUNDLAND AND NOVA SCOTIA PASSENGER STEAMER BRUCE.THE NEWFOUNDLAND AND NOVA SCOTIA PASSENGER STEAMER "BRUCE."
The dimensions of the "Bruce" are 230 feet long, 32 feet 6 inches broad, and 22 feet deep, her gross tonnage being 1250 tons. She has been built with very fine lines, a considerable rise of floor, and with a graceful outline, which gives her the appearance of a large yacht. Our illustration shows the "Bruce" when running at a speed of upward of 15 knots on the measured mile at Wemyss Bay. Not only has the structure of the vessel been skillfully designed, but her internal fittings are admirably arranged. It is really most interesting to note with what ingenuity passenger accommodation of a somewhat extensive character has been provided in so small a vessel. The "Bruce" has berths for seventy first-class and one hundred second class passengers, and the accommodation is of a very luxurious kind. The berths are between the awning and main decks, where there is also a special apartment set apart for ladies, and at the fore end for the officers' quarters. Besides these a large and handsome dining saloon is situated on the main deck, richly upholstered and fitted with unique little window recesses, which besides adding to the appearance of the apartment, furnishes additional dining accommodation. It is done up in dark mahogany panels, fringed with gold. The chairs are upholstered in blue morocco, and the floor is laid with a Turkey carpet. All the other rooms are in dark polished oak. A large smoking room is also provided on the main deck.
The "Bruce" is further fitted with a complete installation of electric lighting, together with an electric search light; has Lord Kelvin's deep sea sounding apparatus and compasses, also Caldwell's steam steering gear and winches, Weir's evaporators and pumps. Alley and McLellan's feed water filters, and Howden's forced draught. She is steam heated throughout, and in every detail of the sanitary arrangements the health and comfort of the passengers have been attended to. Six lifeboats, having accommodation for 250 people, are hung in davits. When fully laden she carries 350 tons of cargo in her holds and 250 tons of coal in her bunkers.
The contract speed for the "Bruce" was 15 knots—and to obtain this Messrs. Inglis fitted her with triple-expansion engines, which we shall illustrate in another impression, having cylinders 26 inches, 42 inches and 65 inches in diameter, with a 42 inch stroke. Steam is supplied from four boilers loaded to a pressure of 160 pounds per square inch. When on the measured mile a mean speed of about 15¼ knots was obtained with an indicated horse power of 2200, the engines running at 90 revolutions per minute.
The vessel has arrived safely at Newfoundland, having performed the voyage at a mean speed of very little under 15 knots, a most satisfactory performance. She has been running some little time on her route and been giving most satisfactory results.—We are indebted to London Engineer for the cut and description.
One phase of the construction of tunnels through the Alps was recently discussed by M. Brandicourt, secretary of the Linnæan Society of the North of France, in the columns of La Nature. He showed that only a few thousand feet below the eternal snows of that region so high a temperature may be found that workmen can scarcely live in it. Nearly all of the other difficulties encountered in those enterprises had been foreseen. This one was a great surprise. It shows how the interior heat of the earth extends above sea level into all great mountainous uplifts on the earth's surface.
During the tunneling of Mont Cenis, says M. Brandicourt, the temperature of the rock was found to be 27.5 degrees C. (81.5 degrees F.) at about 5,000 meters (16,000 feet) from the entrance. It reached 29.5 degrees (86 degrees F.) in the last 500 meters (1,600 feet) of the central part. The workmen were then about 1,600 meters (5,100 feet) below the Alpine summit, whose mean temperature is 3 degrees below zero (27 degrees F.) Thus there was a difference of 32.5 degrees: that is, one "geothermic" degree corresponded to about 50 meters.
This elevation of temperature was not at first regarded with anxiety. Soon a draught would be produced and would ameliorate the situation. It was time, for the disease known as "miner's anæmia" had begun to claim its victims.
The situation at St. Gothard was much more serious. As at Mont Cenis, a temperature of 29 degrees C. (85 degrees F.) was found about 5,000 meters from the portals of the tunnel. But there remained yet 5,000 meters of rock to pierce. In the center of the tunnel there was observed for several days a temperature of 35 degrees (95 degrees F.) Generally it did not vary much from 32.5 degrees (90.5 degrees F.), a sufficiently high degree, if we remember that the men's perspiration was transformed into water vapor, and that the air was nearly saturated with humidity. In these conditions work was very difficult, and the horses employed to remove the debris almost all succumbed.
Man can bear more than animals. In an absolutely dry air he can endure a temperature of 50 degrees (122 degrees F.) But in an atmosphere saturated with water, underground, where the breath of the workmen fills the narrow space with poisonous vapors, a temperature of even 30 degrees (86 degrees F.) entails serious consequences. In a large number of workmen the bodily heat rose to 40 degrees (104 degrees F.) and the pulse to 140 and even 150 a minute. The most robust were obliged to lay off one day out of three, and even the working day was itself reduced to five hours, instead of seven or eight.
According to Dr. Giaconni, who for ten years attended the workmen at Mont Cenis and St. Gothard, the proportion of invalids was as large as 60 to the 100.
More strange yet, the report of the physicians who dwelt at the works notes the presence among the workmen of the intestinal parasites called "ankylostomes," which have been observed in Egypt and other tropical countries, and which are the cause of what scientists call "Egyptian chlorosis" or "intertropical hyperæmia." This pathologic state is observed only in the hottest regions of the earth. The victim becomes thin, pale and dark. He is bathed in continual sweat, devoured by inextinguishable thirst, and the prey of continual fever. And thus, adds Mr. Lentherie, "the most robust mountaineer had only to pass a few months in the depths of the Alps to contract the germs of a tropical disease. Under the thick layer of snow and ice that enveloped him he had to work naked like a tropical negro or an Indian stoker on a Red Sea steamer; and in this Alpine world, where everything outside reminds one of the polar climate, he sweltered as in a caldron and often died of heat."
The bad conditions found at St. Gothard will be met also, very probably, in the new Alpine tunnels that have been projected in recent years—those at the Simplon, St. Bernard and Mont Blanc. It can be predicted that for Mont Blanc in particular the temperature of 40 degrees (104 degrees F.) will be far exceeded. M. de Lapparent even considers that the figure of 55 degrees (131 degrees F.) proposed by some geologists is moderate, and errs by defect rather than by excess.
The engineer Stockalpa, who for four years has directed one of the workshops at St. Gothard, and has made a profound study of this temperature question, does not hesitate to say that under Mont Blanc the temperature will be 33 degrees (91 degrees F.) at three kilometers from the entrance, that it will reach 50 degrees (122 degrees F.) under the Saussure Pass, and 53.5 degrees (128 degrees F.) under the Tacul Peak, falling again to 31 degrees (88 degrees F.) under the White Valley.
These are only probabilities, but they are founded on facts, and we may imagine all the preventive measures that they will render imperative.
The experience that has been acquired in these latter years has indicated the best methods of ventilation and cooling. The compressed air used in the workings produces by its escape a very sensible lowering of the temperature, which can be made still lower by using saline solutions whose freezing point is as low as -20 degrees (4 degrees F.), and which will circulate through pipes along the tunnel. The removal of the debris can be effected by electric locomotives; thus the horses, which use up the precious air, can be doneaway with. The electric light, which can be operated without contamination or consuming the air, will also render great service; these improvements can all be carried out with ease. Together with the preceding, they will form a group of processes that will enable us to gain the victory over the interior heat of the great Alpine tunnels.
Fire EngineAN ENGLISH STEAM FIRE ENGINE.
The machine which we illustrate has lately been constructed by Messrs. Merryweather & Sons, of Greenwich Road, with the view to combining the advantages of both horizontal and vertical steam fire engines. Hitherto the horizontal engine has been considered by some firemen to be less handy of access than the vertical, and the vertical engine has had the undoubted disadvantage of not being stoked from the footplate. By shortening the length of stroke and constructing a special pump, the makers have been able to keep the engine sufficiently high in relation to the boiler to enable the firedoor to be placed directly in the rear of the boiler and underneath the engine, thus enabling the boiler to be stoked en route, and allowing access from the footplate to the starting valve, the suction and delivery connections, the whole of the boiler fittings and feed arrangements. This enables one man to drive and stoke the engine, and to attend to the suction and delivery hoses, and it does not interfere at all with the stability of engine in traveling or at work, as the center of gravity is well below the top of the side frames. Another feature is the absence of a main steam pipe, a bracket being arranged on the cylinders containing the steam passages, to bolt directly onto the top of the boiler. The close proximity of the engine to the boiler renders it peculiarly suitable for cold climates, and times of frost, reducing the chances of the pump or feed arrangements being frozen up. The pump valves are arranged between the barrels, and are all accessible by the removal of one cover, which weighs but 12 lb. The engine, we understand, may be stopped, the cover removed, a damaged valve replaced, the cover put on again, and the engine restarted in two minutes. A slotted link is used with a crankshaft for regulating the length of stroke. All the bearings have large wearing surfaces, and substantial eccentric straps are used, the whole of the motion being simple and accessible. There are three different methods of feeding the boiler, viz., by feed pump driven by the crosshead of the main pump, by forcing water directly into the boiler from the main pump, and by an injector taking its water from a tank either supplied from the main pump or by a bucket when pumping dirty water. All the feed pipes are fitted with strainers where attached to the main pump. Drop feed lubricators are fitted on the cylinders, and an efficient system of lubrication is provided for the rest of the working parts. The carriage frame, hose box, etc., are of the same design as usually employed for engines of this class, with the exception of the fore carriage, which is fitted with a cross spring in the rear, as well as the two longitudinal springs. This arrangement makes the engine run more lightly, and removes much of the strain on the side frames when traveling rapidly on a rough road. The wheels are fairly light for the weight they have to carry, and have gun metal stock hoops with diamond pent rims to prevent the men slipping when mounting in a hurry. The engine and boiler work is brightly polished where-ever possible, and the whole machine has a handsome appearance.—Engineering.
In the exploitation of forests it is an important matter to be able to measure the cubature of trees, and the process most generally employed consists in determining their height and mean circumference, the apparatus used for this latter measurement being compasses having the form of the calipers used by mechanics. The figure indicated is read upon the graduated rule and is called off in a loud voice to another person, who at once writes it down. There are several causes of error: it is possible that the reading may be incorrectly made or improperly called off, or be misunderstood or incorrectly noted. Finally, it is a somewhat fatiguing operation that is often dispensed with and the measurement made by estimate. In order to do away with all such causes of error, M. Jobez, a mining engineer, has had M. Peccaud construct an apparatus that automatically registers all the measurements upon a paper tape analogous to that used in the Morse telegraphic apparatus.
Apparatus for Obtaining the Cubature of Trees.Fig.1.—APPARATUS FOR OBTAINING THE CUBATURE OF TREES.
The registering mechanism (Fig. 1) is fixed to the movable branch that forms the slide of the instrument. It is so arranged that when this branch is slid along the rule carrying the graduations, a gearing causes the revolution of a wheel, D, which carries figures corresponding to such graduation. At the same time, two feed rollers, E, cause a small portion of the paper tape (which is wound upon a spool, A) to move forward and wind around a receiving spool, B. After the apparatus has been made accurately to embrace the trunk of the tree to be measured, it is removed and a pressure given to the lever, H, which applies the paper to the type wheel, D. A special button permits, in addition, of making a dot alongside of the numbers, if it be desired to attract attention to one of the measurements, either for distinguishing one kind of a tree from another or for any other reason.
With this apparatus one man can make all the measurements and inscribe them without any possible error and without any fatigue. It is possible for him to inscribe a thousand numbers an hour, and the tapes are long enough to permit of 4,000 measurements being made without a change of paper. There is, therefore, a saving of time as well as perfect accuracy in the operation.
In order to make the calculations necessary for the estimate, M. Laurand has devised a sliding rule which facilitates the operation and which is based upon the method that consists in knowing the height and mean circumference of the tree. The circumference taken in the middle is divided by 4, 4.8 or 5 according as one employs the quarter without deduction or the sixth or fifth deduced. This first result, multiplied by itself and by the height, gives the cubature of the tree. As for the value, that is the product of this latter number by the price per cubic meter. It will be seen that there is a series of somewhat lengthy operations to be performed, and it is in order to dispense with these that has been constructed the rule under consideration, which, like all calculating rules, consists of two parts, one of which slides upon the other (Fig. 2). Upon each of these there are two graduated scales, or four in all, the first of which is designed for the circumference and the second for the height of the tree, the third for the price of the cubic meter and the fourth for the total result, that is, the value of the entire tree. The arrangements are such that, after the number corresponding to the circumference of the tree has been brought opposite that corresponding to its height, the result will be found opposite the price per cubic meter.
Drawing of a complex ruler.Fig.2.—LAURAND'S CALCULATING RULE.
Thus, in the position represented in the figure, we may suppose a tree having a circumference of 2.5 m. and a height of 3.2 m.; then, if a cubic meter is worth 25 francs, the tree will be worth 20 francs.
In order to simplify the calculations and the construction of the rule, no account is taken of points; but this is of no importance, since the error that might be made in misplacing one would be so great that it would be immediately detected. A 2 franc tree would not be confounded with a 20 or a 200 franc one. As an approximation, the first two figures of the result are obtained accurately; and that suffices, because, since the whole is based upon an approximate measurement, which is the mean circumference of the tree, we cannot exact absolute precision in the results. The essential thing is to have a practically acceptable figure.—La Nature.
Egypt's population, according to the census taken last June, is 9,750,000, more than double the population in 1846. The foreign residents are 112,000; of these, 38,000 are Greeks, 24,500 Italians, 19,500 Britishers, including the army of occupation, and 14,000 French subjects, including Algerians and Tunisians. Twelve per cent. of the native males can read and write; the other Egyptians are illiterate. Cairo has 570,000 inhabitants, Alexandria 320,000, Port Said 42,000, and Suez 17,000.
(Member of the Society.)
Moulding machines may be classed under three heads. First, machines which only ram the moulds, and, when the ramming is done by means of a side lever, by hand, are generally called "squeezers." Second, machines which only draw the patterns, the ramming being accomplished by the usual hand methods. Third, machines which both ram the moulds and draw the patterns, ramming either by a hand-pulled lever or by fluid pressure on piston or plunger and drawing the patterns through a plate called a "stripping plate" or "drop plate"—till recently the usual method—or without the use of this plate fitting everywhere to pattern outline at the parting surface, the patterns being effectively machine guided in either case.
It is to the third class that the machine which is used to illustrate the subject of this paper belongs, and which would seem to have enough that is novel in the application of machinery to the foundry to merit the attention of the society.
Fig. 1. ORDINARY METHOD OF DRAWING PATTERN SPIKE AND RAPPER.Fig.1.—ORDINARY METHOD OF DRAWING PATTERN SPIKE AND RAPPER.
At the risk of appearing pedantic, but with a view to developing an appreciation of the true function of the method of pattern drawing used in this machine, attention is called to the following sectional views of moulds and ways of drawing patterns occurring in machine moulding. Fig. 1 shows an ordinary "gate" of fitting patterns being drawn from the drag or nowel part of the mould by means of a spike and rapper wielded by the moulder's hand after cope and drag have been rammed together on a "squeezer" and cope has been removed. Frequently the pernicious "swab" is used to soak and so strengthen joint outlines of the sand before drawing patterns, in such cases as this. In this case, before cope is lifted, these patterns must be vigorously rapped through the cope; an amount depending (and so does the size of the casting) upon the mood and strength of the moulder.
Fig. 2 shows the stripping or drop plate method of drawing patterns.
Fig. 2. STRIPPING PLATE METHOD OF DRAWING PATTERNS.Fig.2.—STRIPPING PLATE METHOD OF DRAWING PATTERNS.
In this method the patterns are not rapped at all and are drawn in a practically straight line so that the mould is absolutely pattern size.
The stripping plate is fitted accurately to every outline at the joint surface of the patterns, obviously at considerable expense, and, of course, at the instant of drawing the patterns, supports the joint surface of the mould entirely. This is, at first sight, an ideal method of drawing patterns, and it has for years been the only method practiced on machines. It has two disadvantages. The patterns are separated from the stripping plate by the necessary joint fissure between the two. Fine sand continually falls into this and, adhering to the joint surfaces more or less, grinds the fissure wider. This leads to a gradual reduction of size of patterns on vertical surfaces and a widening of the joint fissure often to such an extent that wire edges are formed on the mould, causing, on fine work, "crushing" and consequently dirty joints. A nicely fitted but worn plate of twenty-four pieces which had cost, at shop expense only, $250, was recently replaced by a plate of twenty-eight pieces, fitted ready for the machine under the new system about to be described, for not more than $25.
The stripping plate method has another drawback, not always appreciated, probably because accepted as inevitable. Stripping plate patterns are not rapped, and there frequently occur on surface of patterns, remote from the action of the stripping plate, rectangular corners just as important to mould sharply as those at the parting line. Such corners have either to be filleted or "stooled" in stripping plate work, and neither method often is practicable. When the entire pattern and plate are vibrated so that the corners where the pattern joins the plate draw perfectly, as they do in the machine to be described, it is obvious that similar corners anywhere on pattern surface will draw equally well.
The vibrating of patterns, or rather of moulds, during the operation of drawing the patterns possesses little of novelty. Ever since a bench moulder's neighbor first rapped the bench while he lifted a cope or drew a pattern, the thing has been done in one way or another. In fact, machines are now and then found on the market in which a device like a ratchet or other mechanical means for jarring the machine structure during pattern drawing renders the working of easy patterns without stripping plates possible.
The idea of applying a power driven vibrator directly to the plate carrying the patterns to thus vibrate them independently of other parts of the machine and the flask and sand has been the subject of the issue of patents to Mr. Harris Tabor, and the various figures shown will serve to illustrate the mechanism.
Briefly, the operation of the machine is as follows: The ramming head shown thrown back at the top of the machine is drawn into a vertical position after flask has been placed and filled with sand. The 3-way cock shown at the extreme left is then quickly opened, admitting compressed air of 70 to 80 pounds pressure to the inverted cylinder shown at the center of the cut. The cylinder, with the entire upper portion of the machine, is thus driven forcibly up against the ramming head, flask, sand and all. Often a single blow suffices to rain the mould—often the blow is quickly repeated, according to the demands of the particular mould in hand. Gravity returns the machine to its original position, as the 3-way cock opens to exhaust. After pushing the ramming head back and cutting sprue, if the half mould is cope, the operator seizes the lever shown just inside the 3-way cock at the right, and, drawing it forward and down, raises the outer frame of the top of machine containing the flask pins, with flask and sand thereon, away from the patterns, thus drawing them from the sand. Just as he seizes the pattern drawing lever with his right hand, he presses with his left on the head of a compression valve shown at the left side of top of machine, thus admitting air to the pneumatic vibrator already referred to.
Fig. 3 Vibrator MachineFig.3.—POWER DRIVEN VIBRATOR MACHINE.
Fig. 3, a rear view of the machine, shows at the top center, with its inlet hose hanging to it, this vibrator, which is shown in section in Fig. 4. It consists simply of a double acting elongated piston having a stroke of about5/16inch in a valveless cylinder and impacting upon hardened anvils at either end at the estimated rate of 5,000 blows per minute.
Fig. 4 Vibrator Cross-sectionFig.4.—SECTION THROUGH VIBRATOR.
The method of communicating the rapid yet small oscillations of the vibrator to the patterns and yet keeping them from being transmitted to the rest of the mechanism is this:
A frame, called a vibrator frame, to which the pneumatic vibrator is bolted and keyed, is shown in Fig. 5. To this frame the plate carrying the patterns, often, in cases of patterns having irregular parting lines, forming one and the same casting with the patterns, is fastened by the four machine screws, the small tapped holes for which are shown in the corners. In fact, in changing patterns, the process consists of simply removing these four machine screws, taking up the pattern plate and screwing to the vibrator frame the new pattern plate. The vibrator frame itself is secured to the machine structure by the four larger bolts, the holes for which are shown in the inner corners. These bolts are, as shown in Fig. 7, surrounded by thick bushings. These bushings are elastic to such a degree as to absorb the sharp vibrations of vibrator frame and patterns, while so firm and well fitted as to hold patterns accurately to their position.
Fig. 5 Vibrator FrameFig.5.—VIBRATOR FRAME.
The action of the vibrator is such as to give to the entire pattern surface an exceedingly violent shiver, making it impossible that any sand should adhere to this surface, while the magnitude of the actual movement of the pattern is so slight that it is found to fill the mould so completely that it is impracticable to draw it a second time without rapping. Yet, so truly are the patterns held and so little disturbed from their original position, that it is perfectly practicable to return patterns to a mould having the finest ornamental surface in the ordinary practice of "printing back."
In cases where deep pockets of hanging sand occur, which cannot be held during lifting off and rolling over, machines are arranged to roll the flask over in their operation and draw the patterns up under the influence of the pneumatic vibrator, though, owing to the time consumed in the rolling over process (and each operation counts in seconds on a moulding machine) this style of machine is not usually as rapid in its working as the simpler type, in which the flasks come off in the same way they go on.
Fig. 6 PatternsFig.6. SET OF PATTERNS FITTED TO PLATES.
Fig. 6 shows a set of patterns as they are ordinarily fitted to plates for this machine. Round holes will be noticed at places in the plate surface. These are openings for the insertion of what are called "stools."
When it is found necessary to support the sand surface at any point, or generally, round holes are drilled through either plate or pattern surface and loose cylindrical pieces are dropped into these holes, their upper end surfaces being flush with the plate or pattern surface and their lower ends resting on the plate called, from this use, a stool plate. This plate appears in Fig. 7 at A and is hung solidly by the brackets shown at B from the frame which carries the flasks, so that it has the same upward motion as the flasks, and the upper ends of the stools remain in contact with the sand of the mould until same is lifted from machine. Fig. 7, showing a vertical section through a machine, will make perfectly clear the position and action of these stools.
Fig. 7 VERTICAL SECTIONS FITTED TO PLATES.Fig.7. VERTICAL SECTIONS FITTED TO PLATES.
As illustrating the importance of being able to work without stripping plates on a line of work which is much more extended than that possible with them, we may say that a machinist with a drill press supplied with split patterns and planed pattern plates has matched and fixed five sets of from four to eight pieces in a day: and wooden patterns fitted for temporary use in the same way are of frequent occurrence when it is not thought wise to go to the expense of metal patterns on account of the relatively small number of castings to be made from them.
It is not perhaps too much to say that pattern expense is not the final evil of the costly and not durable stripping plate patterns.
[1]Paper presented at the New York meeting (December, 1897) of the American Society of Mechanical Engineers, and forming part of volume xix. of the Transactions.
[1]Paper presented at the New York meeting (December, 1897) of the American Society of Mechanical Engineers, and forming part of volume xix. of the Transactions.
One of the most recent important events in the history of chemistry was the discovery by an English professor that a substance corresponding in every respect to India rubber may be produced from oil of turpentine.
Dr. W.A. Tilden, professor of chemistry in Mason College, Birmingham, began a series of experiments with a liquid hydrocarbon substance, known to chemists as isoprene, which was primarily discovered and named by Greville Williams, a well known English chemist, some years ago as a product of the destructive distillation of India rubber. In 1884, says The New York Sun, Dr. Tilden discovered that an identical substance was among the more volatile compounds obtained by the action of moderate heat upon oil of turpentine and other vegetable oils, such as rape seed oil, linseed oil and castor oil.
Isoprene is a very volatile liquid, boiling at a temperature of about 30 degrees Fahrenheit. Chemical analysis shows it to be composed of carbon and hydrogen in the proportions of five to eight.
In the course of his experiments Dr. Tilden found that when isoprene is brought into contact with strong acids, such as aqueous hydrochloric acid, for example, it is converted into a tough elastic solid, which is, to all appearances, true India rubber.
Specimens of isoprene were made from several vegetable oils in the course of Dr. Tilden's work on those compounds. He preserved several of them and stowed the bottles containing them away upon an unused shelf in his laboratory.
After some months had elapsed he was surprised at finding the contents of the bottles containing the substance derived from the turpentine entirely changed in appearance. In place of a limpid, colorless liquid the bottles contained a dense sirup, in which were floating several large masses of a solid of a yellowish color. Upon examination this turned out to be India rubber.
This is the first instance on record of the spontaneous change of isoprene into India rubber. According to the doctor's hypothesis, this spontaneous change can only be accounted for by supposing that a small quantity of acetic or formic acid had been produced by the oxidizing action of the air, and that the presence of this compound had been the means of transforming the rest.
Upon inserting the ordinary chemical test paper, the liquid was found to be slightly acid. It yielded a small portion of unchanged isoprene.
The artificial India rubber found floating in the liquid upon analysis showed all the constituents of natural rubber. Like the latter, it consisted of two substances, one of which was more soluble in benzine or in carbon bisulphide than the other. A solution of the artificial rubber in benzine left on evaporation a residue which agreed in all characteristics with the residuum of the best Para rubber similarly dissolved and evaporated.
The artificial rubber was found to unite with natural rubber in the same way as two pieces of ordinary pure rubber, forming a tough, elastic compound.
Although the discovery is very interesting from a chemical point of view, it has not as yet any commercial importance. It is from such beginnings as these, however, that cheap chemical substitutes for many natural products have been developed. Few persons outside of those directly connected with rubber industries realize the vast quantities imported yearly into this country. Last year there were brought into United States ports, as shown by the reports of the customs officers, no less than 34,348,000 pounds of India rubber. The industry has been steadily progressive since the invention of machinery for manufacturing it into the various articles of everyday use. The wonderful growth of the India rubber interests in this country will be seen from the statistics compiled in the tenth census.
In 1870 there were imported 5,132,000 pounds at an average rate of $1 per pound; in 1880 the imports were 17,835,000 pounds, at an average price of 85 cents per pound; in 1890 31,949,000 pounds were imported, at an average price of 75 cents per pound. The present price of India rubber varies from 75 cents per pound for fine Para rubber to 45 cents per pound for the cheapest grade.
It will be seen that, notwithstanding the increase in importations, the price of the raw material remains at a comparatively high figure. Many experiments have been made to find a substance possessing the same properties as India rubber, but which could be produced at a cheaper rate.
Many of the compositions which have been invented have been well adapted for use for certain purposes and have been used to adulterate the pure rubber, but no substance has been produced which could even approach India rubber in several of its important characteristics. There has never been a substance yet recommended as a substitute for rubber which possessed the extraordinary elasticity which makes it indispensable in the manufacture of so many articles of common use.
Great hopes were at one time placed in a product prepared from linseed oil. It was found that a material could be produced from it which would to a certain extent equal India rubber compositions in elasticity and toughness.
It was argued that linseed oil varnish, when correctly prepared, should be clear, and dry in a few hours into a transparent, glossy mass of great tenacity. By changing the mode of preparing linseed oil varnish in so far as to boil the oil until it became a very thick fluid and spun threads, when it was taken from the boiler, a mass was obtained which in drying assumed a character resembling that of a thick, congealed solution of glue.
Resin was added to the mass while hot, in a quantity depending upon the product designed to be made, and requiring a greater or less degree of elasticity.
Many other recipes have been advocated at different times to make a product resembling caoutchouc out of linseed oil in combination with other substances, but all have failed to give satisfaction, save as adulterants to pure rubber.
Among the best compounds in use in rubber factories at present is one made by boiling linseed oil to the consistency of thick glue. Unbleached shellac and a small quantity of lampblack is then stirred in. The mass is boiled and stirred until thoroughly mixed. It is then placed in flat vessels exposed to the air to congeal.
While still warm the blocks formed in the flat vessels are passed between rollers to mix it as closely as possible. This compound was asserted by its inventor to be a perfect substitute for caoutchouc. It was also stated that it could be vulcanized. This was found to be an error, however. The compound, upon the addition of from 15 to 25 per cent. of pure rubber, may be vulcanized and used as a substitute for vulcanized rubber.
Compounds of coal tar, asphalt, etc., with caoutchouc have been frequently tested, but they can only be used for very inferior goods.
The need for a substitute for gutta percha is even more acute than for artificial India rubber. A compound used in its stead for many purposes is known as French gutta percha. This possesses nearly all the properties of gutta percha. It may be frequently used for the same purposes and has the advantage of not cracking when exposed to the air.
Its inventors claimed that it was a perfect substitutefor India rubber and gutta percha, fully as elastic and tough and not susceptible to injury from great pressure or high temperature.
The composition of this ambitious substance is as follows: One part, by weight, of equal parts of wood tar oil and coal tar oil, or of the latter alone, is heated for several hours at a temperature of from 252 to 270 degrees Fahrenheit, with two parts, by weight, of hemp oil, until the mass can be drawn into threads. Then one-half part, by weight, of linseed oil, thickened by boiling, is added. To each 100 parts of the compound one-twentieth to one-tenth part of ozokerite and the same quantity of spermaceti are added.
The entire mixture is then again heated to 252 degrees Fahrenheit and one-fifteenth to one-twelfth part of sulphur is added. The substance thus obtained upon cooling is worked up in a similar manner to natural India rubber. It has not been successfully used, however, without the addition of a quantity of pure rubber to give it the requisite elasticity.
A substitute for gutta percha is obtained by boiling the bark of the birch tree, especially the outer part, in water over an open fire. This produces a black fluid mass, which quickly becomes solid and compact upon exposure to air.
Each gutta percha and India rubber factory has a formula of its own for making up substances as nearly identical with the natural product as possible, which are used to adulterate the rubber and gutta percha used in the factory. No one has as yet, however, succeeded in discovering a perfect substitute for either rubber or gutta percha.
The history of chemistry contains many instances where natural products have been supplanted by artificial compounds possessing the same properties and characteristics. One of the most notable of these is the substance known as alizarine, the coloring matter extracted from the madder root. This, like India rubber, is a hydrocarbon.
Prior to 1869 all calico printing was done with the coloring matter derived from the madder root, and its cultivation was a leading industry in the eastern and southern portions of Europe.
In 1869 alizarine was successfully produced from the refuse coal tar of gas works and the calico printing business was revolutionized.
The essence of vanilla, made from the vanilla bean, and used as a flavoring extract, has been supplanted by the substance christened vanilla by chemists, which possesses the same characteristics and is made from sawdust.
Isoprene, from which Dr. Tilden produced India rubber, is comparatively a new product, as derived from oil of turpentine. It yet remains to be seen whether rubber can be synthetically produced certainly and cheaply. The result of further experiments will be awaited with interest, as the production of artificial rubber at moderate cost would be an event of enormous importance.
The best means of producing these effects is by printing from a steel plate or lithographic stone on thin transfer paper, which, in turn, is made to give up the design to the surface of the glass, the exposed portions of the latter being then etched with acid.
In preparing the steel plate, a coating of varnish is prepared by mixing 200 parts by weight of oil of turpentine, 150 of Syrian asphaltum, 100 of beeswax, 50 of stearin, and 50 of Venice turpentine in the warm. The design is then copied in outline by tracing from the original, the shading being reproduced in a less detailed manner, but with fewer and bolder strokes, in order to adapt the picture to the process. It is then pricked through the tracing paper on to the varnish coating of the plate, and, after clearing out the lines with graving needles, the plate is etched with a mixture of 1 vol. of water and 4 to 7 vols. of nitric acid, either by application or immersion; in the latter event the back of the plate must be varnished over. When the metal is bitten by the acid to about 1-75 of an inch in depth, the operation is finished.
To transfer the design to the glass it is printed from the steel plate on to thin silk paper, the ink used being compounded from 500 parts of oil of turpentine, 1,500 of Syrian asphalt, 500 of beeswax, 400 of paraffin, and 300 of thick litho varnish. The printing is performed in the usual manner, and the transfer laid on the warmed surface of the glass sheet or ware to be decorated, rubbed over uniformly with a cloth to make the ink adhere to the glass, and then the paper is moistened and taken off again, leaving the imprinted design behind. It is well to have the ink fairly thick, and rely on warmth to impart the necessary fluidity; otherwise the design may come away with the paper in patches, and be imperfect.
For etching in the design on the glass, the edges of the latter are coated with the protective varnish, and then hydrofluoric acid is brushed over the exposed portions, which are thereby corroded, leaving the parts covered by the ink standing in relief. According as a clear or frosted etching is desired, the etching liquid is modified, being, for the latter purpose, composed of 500 parts of ammonium fluoride, 100 of common salt, 300 of fuming hydrofluoric acid and 30 of ammonia. This is brushed over the glass two or three times, and then rinsed off with lukewarm water. For deep etching, hydrofluoric acid is diluted with 1½ vols. of water and stored for twenty-four hours before use. The objects are immersed in the baths for thirty to fifty minutes, and kept quite still the while. If the etching is to be left clear, the acid is neutralized by boiling the glass in soda, but if to be frosted afterward it is coated with the first named etching liquid while still damp. Finally, the ink is washed off with turpentine, the glass rubbed over with sawdust, washed in hot lye and rinsed with water.
Grained or lined designs can be very suitably printed from a litho stone, on paper faced with a mixture of 1,500 parts of water, 250 of wheaten starch, 1,000 of glycerine and 200 of a thick solution of gum arabic, the ink for printing being prepared by melting and mixing 500 parts of pure tallow, 250 of white beeswax, 250 of liquid mastic, and 150 of pale resin, with 100 parts of lampblack, 5 of minium, and 500 of litho varnish. In transferring the design to the glass, the latter, if flat, may be passed between India rubber rollers or protected by layers of gutta percha when the pressure is applied. The impression produced by this lithographic process has to be strengthened to enable the thin coating of ink to resist the etching liquid, and this is done by dusting powdered resin over the printed surface of the glass, brushing off all that does not adhere, and causing the remainder to attach itself to the ink by means of warmth, and so form an impervious covering. The further treatment is the same as that already described. These methods are particularly suitable for reproducing landscapes, etc., on thinly flashed glass of various colors.—Diamant.
Slate is, as we know, merely a variety of argillite. Slate quarries are found in England, Switzerland and Italy, but it is in France especially that the industry has been most extensively developed by reason of the large deposits that underlie its surface, particularly in the province of Anjou, where they extend from Trelaze to Avrille, a distance of six miles, and in the department of Ardennes, at Remogne, Fumay, etc.
Normandy, Brittany, Dauphiny and Marne likewise possess quarries, although they are not so productive.
The exploitation is commonly done in open quarry. After the vegetable mould (which in this case is called "cover") has been removed, we meet with a solid slate which it is difficult to split into laminæ, and it is not until a depth of at least fifteen feet is reached that we find a material that is fit to be exploited. All the best beds of slate, in fact, improve in quality in proportion as they lie deeper under the surface, near to which they have little value. Without entering into details as to the exploitation of this product, let us say that the blocks have to be divided in the quarry, since, in the open air, they rapidly lose the property of readily splitting into thin, even laminæ.