metal, and soldering irons of various kinds are required. Autogenous Soldering takes place by the fusion of the two edges of metals themselves without interposing another metallic alloy as a bond of union. This is accomplished by directing a jet of burning hydrogen gas from a small movable beak upon the two surfaces or edges to be soldered together. Metals thus joined are much less apt to crack asunder at the line of union by differences of temperature, flexibility, etc., than when the common soldering process is employed. This method of soldering is especially of great advantage in chemical works for joining the edges of sheet lead for sulphuric acid chambers and concentration pans, because any solder containing tin would soon corrode. Ordinary Soft Solder, an alloy of tin and lead, is best adapted for most metals, with the exception of cast-iron, worked in the various industries. Its composition varies very much, about equal parts of the metals being generally taken; 2 parts of tin to 1 of lead furnishing what is called "weak soft solder," and 2 parts of lead to 1 of tin "strong soft solder." A composition consisting of: Copper is the best material of joining iron to iron whether wrought or cast. It unites the two surfaces very firmly and, by reason of its natural ductility and toughness, allows of the soldered articles being bent into almost any shape. Brass Hard Solder consists of a mixture of brass and zinc to which is sometimes added a small portion of tin. Wrought or rolled brass being more homogeneous, and not likely to contain an undue proportion of zinc, should be preferred to cast-brass in preparing the solder. The proportions of brass and zinc vary according to the purpose intended; addition of zinc increases the fusibility but decreases the ductility and also the durability of the solder. A very good hard solder for cast-steel, wrought-iron, steel, copper, and brass (with the exception of castbrass) is obtained by melting 7 parts of brass shavings together with 1 of zinc, keeping the mixture in flux for not longer than 6 to 7 minutes, and then pouring out. Hard Solder containing Tin. In preparing this solder it is best to melt the brass and zinc separately in 2 crucibles, so that they become liquid at the same time. The zinc is then carefully, and with quick and constant Tin 1 part and lead 2 parts melts at 441.50 F. stirring, poured in the brass previously 66 1 part "371.7° F. "340.2° F. 1 66 66 1 66 1 66 Darcet's Metal is an excellent soft solder consisting of lead and bismuth each 8 parts and tin 3 parts. Hard Solders. Cast-iron may be used as a solder for wrought-iron, but, being very refractory and brittle, it is but seldom used. skimmed. b. Softer Hard Silver Solder for after- therefore requiring a soldering, i. e., for soldering articles solder: having parts already soldered and I. more fusible II. III. IV. V. v1. VII. VIII. IX. Good Hard Solder used for soldering brass is prepared from an alloy of parts of copper with 4 of brass and 10 of tin. The copper and brass are first melted and the tin is then added. When the whole is melted together it is poured upon a bundle of twigs held over a tub of water, into which it falls in granulations. The granulated metal is then dried and pounded to the required fineness in a mortar. By adding to this alloy 2 parts of zinc a still more fusible solder is obtained. For soldering platinum, fine gold cut up in small pieces is used. An Excellent Soft Solder is obtained by melting together equal parts of bartin and lead. It is used for soldering tin plates together, and gives very good results. The following table gives a number of alloys for soft solder and their respective melting points: No. 8 is used for soldering cast-iron and steel, sal-ammoniac or rosin serving as a flux. Copper, brass, and bronze can also be soldered with the same alloy and the same flux. For soldering tin-plate and sheet-iron chloride of zinc is used as a flux with the same solder. Lead and tin-pipes are soldered with Nos. 6, 7, and 8, using rosin and olive oil as flux. Silver Solder for Plated Ware. Melt together silver 64 parts and brass 40. Soft Solder for Cast Britannia Metal. Melt together lead 10 parts, tin 16. Solder for Pewter. Melt together tin 30 parts, lead 15, and bismuth 3 to 9. Hard White Solder is composed of copper 24 parts, zinc and tin each 8. Hard Yellow Solders. 1 consists of copper 13 parts and zinc 10. 2. This is especially suitable for coppersmiths. It is composed of zinc 49.5 parts and copper 50.5. Solder for Gold on Aluminium Bronze. Copper 8 parts, aluminium 12, and zinc 80, melted together in the order mentioned. For larger articles : Copper 4 parts, aluminium 6, and zinc 90. Three Excellent Hard Solders found in commerce are composed as follows: Copper Zinc Tin Lead Parts. Parts. Parts. Parts. A. Golden yellow 53.50 43.33 2.12 Tin To Solder Brass and Sheet-tin. the brass where it is to be soldered, and use a solder consisting of 2 parts tin and 1 lead. To Solder Iron and Steel. For large pieces of iron or steel, copper or brass is used as solder. Place a thin strip of copper or brass along the junction, bind the plates together with wire, and cover them an inch deep with clay free from sand. For soldering iron to iron bring the plates, when dry, to a white heat, and then plunge them into cold water; for iron to steel or steel to steel cool slowly from the white heat. The vitrified clay is then broken off. For smaller articles prepare a solder by granulating a mixture of 8 parts of brass with 1 of zinc. Mix this solder with borax and spread it over the articles to be joined. For very small articles a solder prepared by melting together 6 parts of brass, 1 of zinc, and 1 of tin is used. The solder is beaten into thin plates, which are applied, together with borax, to the surfaces of the articles to be soldered. Very small and delicate articles are best soldered by gold, either pure or mixed with 2 parts of silver and 3 of copper. To Solder Steel on Sheet-iron. Melt borax in an earthenware pot, and mix it with part of sal-ammoniac. Cool it upon an iron plate, and add an equal weight of lime. When iron and steel are to be soldered together bring them first to a red heat, and spread the above mixture over them. The mixture melts and becomes liquid like sealing-wax. The pieces of metal are replaced in the fire and heated again, but not nearly as strong as for ordinary soldering; they are then taken out and the two surfaces united by hammering. The same process is also recommended for soldering sheet-iron tubes. Soldering without a Soldering Iron. Pieces of brass, etc., can be soldered without it being possible to detect the joint by filing the pieces so that they fit exactly, moistening them with a soldering liquid, then placing a piece of smooth tin-foil between them, tying them together with wire, and heating over a lamp or fire until the tin-foil melts. With good soft solder most all soldering can be done over a lamp without the use of soldering iron. The different degrees of fusibility of solders can also be advantageously used for several solderings and joints on the same piece. By soldering first with a fine solder composed of lead 2 parts, tin 1, and bismuth 2 there will be no danger of melting when close to the jointed part another piece is soldered on with solder composed of lead 4 parts, tin 4, and bismuth 1. The following soldering liquid is the best to use: Equal parts of water and hydrochloric acid saturated with zinc. Soldering Liquid Causing no Rust is prepared as follows: Dissolve small pieces of zinc in hydrochloric acid until the acid ceases to effervesce. Then add about part of the solution of spirit of sal-ammoniac, which neutralizes all acid, and finally dilute the whole with an equal quantity of water. This soldering liquid causes no rust on iron or steel, and does excellent service in all soldering and also in tinning operations. Another Soldering Liquid Free from Acid is prepared by mixing 10 parts of pure hydrochloric acid with 5 of water, and adding gradually to the mixture 5 parts of zinc cut up in small pieces. It is best to use an earthenware or glass vessel with a wide neck, and, by reason of the escaping gases being very poisonous, to perform the work in the open air. When all the zinc has been added stir frequently with a wooden rod during the first day; the next day heat the vessel gently by placing it in hot water or hot sand, and then place the mixture aside for clearing. In a few days pour off the clear fluid, and add a solution of part of sal-ammoniac in 2 of water; stir thoroughly and put the ready liquid in earthen jars or glass bottles. The zinc remaining in the vessel is rinsed off with water, dried, and kept for future use. If a stronger liquid is desired, the last 2 parts of water may be omitted and the sal-ammoniac directly dissolved in the solution of zinc. Simple Method of Soldering Small Articles. Moisten the surfaces of the metals to be soldered with a feather dipped in a solution of sal-ammoniac, and fit the joint with tin-foil cut to the exact size, and heat the metals sufficiently to melt the tin-foil. When cold the surfaces will be found firmly cemented together. To Solder Saws. A piece of charcoal, a blowpipe, some spelter and borax are required. File the ends of the saw smooth, so that one side laps over the other; fit the teeth opposite each other, and bind it with iron wire to keep in place. Then moisten the lap with borax dissolved in water and place the saw on the charcoal. Place the broken parts near a gas jet, sprinkle the parts previously wetted with the spelter, and blow the flame of gas until the spelter runs; let it get cool before removal. When quite cold file it flat with the other part of the saw. SUGARS, GLUCOSE, ETC. Preparation of Milk Sugar. By the former process of evaporating the whey in order to gain the milk-sugar, a large part of it, by reason of the percentage of acid, passed over into non crystallizable lactose. By Engling's evaporated mass with 10 to 25 parts process the whey is neutralized with by weight of boiling hot methyl alwhiting, then evaporated to one-half cohol, and pour the resulting thin its volume and allowed to settle. The syrup in conical moulds, which can be clear whey is then drawn off from the closed. Crystallization will be comprecipitate, consisting of albumen and plete in 2 or 3 days, when what recalcium phosphate, and further evap- mains liquid is expelled by suction. orated. The sugar separates from the purified solutions in cohering lamina and crusts. The mother lye, by being further evaporated, yields a second crystallization. The remaining thick lye can be still further worked into sugar by dialysis. By this process 100 parts of summer whey yield 4 parts of refined milk-sugar. By allowing the whey to freeze and removing from time to time the ice-crust formed, a solution rich in sugar is obtained in a comparatively short time, and which is purer than that gained by evaporation, since the fat, albumen, and salts mostly combine with the ice. An experiment to obtain milk-sugar by this process resulted in a yield of part of milksugar, white as snow, from 10 parts of whey, the result being still better from winter whey, naturally poor in sugar, 100 parts of which yielded 2 parts of milk-sugar. Improvement in Refining and Crystallizing of Starch Sugar (Glucose), Commercial glucose is melted and mixed with 70 to 80 per cent. of spirit of wine of 80° Tralles, or with pure pyroligneous spirit. To the resulting syrupy mixture add pulverized glucose, and allow the whole to congeal at a temperature of above 86° F., stirring it frequently. The syrup obtained in the manufacture of starch can also be treated in this manner. The resulting paste is pressed and treated in the centrifugal machine, and the alcohol regained by distilling in a vacuum. To prepare solid transparent glucose (dextrose hydrate C, H, O, H, O) concentrate in a vacuum a solution of glucose to 46° (weighed at 90°) and allow it to crystallize in moulds at a temperature from 95° to 120° F. At a lower temperature it crystallizes in wart-like masses. 2 Refining and Preparation of Anhydrous Glucose. Evaporate in a vacuum an entirely colorless and clear solution of glucose until a sample can scarcely be kneaded. Then mix the For producing dense and solid sugar, saturate the porous mass taken from the moulds with a mixture of 100 parts of concentrated syrup and 80 to 100 parts of pyroligneous spirit and allow it to crystallize at an ordinary temperature. When the desired density has been obtained, remove the liquid portion by suction and wash the sugar with methyl alcohol. The methyl alcohol remaining in the loaves is distilled off by bringing the loaves into a vacuum pan, a temperature of 86° F. being sufficient at the start, and need only be raised towards the end of the operation to 120° to 140° F. The pyroligneous spirit is regained by distillation from the fluid drawn off by suction. Apparatus and Process for the Fabrication of Starch, Glucose, and Hard Grape Sugar (Dextrose), by Wm. T. Jepp, of Buffalo, N. Y. Through the hopper 4' (Fig. 40) the corn, etc., to be worked is conveyed into the closed steeping vat A filled with water of about 140° F., and distributed by an apparatus over the entire inner surface of the vat. The material sinks down, while the foreign admixtures are removed by a discharge pipe. After 48 hours the water is drawn off, and the corn conveyed by an elevator to the hopper B', and from here to the mill B2, from whence it passes to the shaking sieve C, upon which falls a constant stream of water. The starch passes through the sieve, while the bran remains behind and is carried by a transport screw placed underneath the sieve to the elevator C", and is conveyed by this to the crushing apparatus D, consisting of two rubber collars between which passes a wire cloth. The bran is here freed from moisture and starch, the bran remaining upon the wire cloth while the starch is collected in a basin beneath the cloth and runs from here into the settling boxes E, where it is treated with chemicals in order to separato |