Brass (metal)

“ When heat, elongating the balance ring, causes it to vibrate more slowly, the brass, expanding more than the steel, bends the free ends of the cut rim toward the center, thus decreasing the diameter of the balance and quickening the vibration. On the other hand, when cold, contracting the ring tends to quicken the vibration of the balance, the contraction of the brass rim draws the free end outward, making the diameter larger and the vibration slower in consequence. The compensation balance is also made with brass as the inner metal and aluminum outside. ”

“ There are tinned brass vessels with incised decorations, sculptured vessels of brass, brass incrusted with copper and copper incrusted with silver, but which can be called the baser and which the richer metals when all assume shapes of such wondrous beauty as the lotas and sarais, and are decorated with designs so pleasing and with a skill so perfect with damascened work, incrustations or enamel? The metal excipient is forgotten in the art. ”

“ Brass is not a pure metal, but is what is called an alloy, that is, a mixture of various metals. It is composed of copper and zinc in such proportions as may be necessary to [103] obtain various degrees of hardness and colour, according to the use for which the compound is to be employed. The best proportions for common brass are about two parts of copper to one part of zinc. Formerly brass was made by heating copper with calamine (which is the ore of zinc) and charcoal, but it is now formed from melting the two metals together. ”

“ Of domestic metal-work there are not many early pieces. In Fig. 82 is shown a cup or ewer of brass with artistic handle and spout ornamented with a grotesque mouth; the date assigned to it is 1570. It may be seen in the Victoria and Albert Museum, where also is deposited a fine seventeenth-century ewer or tankard with plain cylindrical body and a deep and long spout with fancy handle (see Fig. 81) . There is also a trumpet of brass, dated 1738, in the same gallery; it has upon it the owner's monogram, "S.M.A.," ensigned with a count's coronet and crest. ”

“ Upon analysis the brass was found to contain 70%-75% copper, 20%-30% zinc, and other trace elements. The blades, cocking levers, and button releases of lancets and scarificators were found to be made of ferrous metal (iron or steel) . In addition to the typical brass pieces, a number of “white metal” pieces were analyzed. (The term “white metal” is used to designate any undetermined silver-colored metal alloy.) Those white metal pieces dating from the eighteenth century (a Swiss or Tyrolean fleam and an English veterinary spring lancet) were found to be composed entirely of ferrous metal. ”

“ The collector of copper and brass looks with regret on the early fire-making apparatus in that iron was the chief metal employed. Nevertheless there are some objects associated with fire-making manufactured in brass. There are some well-known collectors who have specialized on fire-making appliances and early lamps. Among fire-making appliances are those of the percussion type, commencing with iron pyrites, flint, steel, and tinder. Some of the earlier tinder boxes were made of brass, although the majority were of wood and tin ”

“ During the sixteenth century much progress was made in metal-founding. The Worshipful Company of Founders was busy. Many "battery" works were set up in England, and there brass was hammered or battered into shape. Thus brass-workers were engaged in making useful pots and pans, now in their much worn state eagerly sought after by the collector. Some worked with the ladle and crucible, others with the hammer and anvil or wood block. ”

“ Some of the articles manufactured of brass, are forged to the required form, and others are made of rolled sheets; but, in most cases, they pass through the hands of the brass-founder, who liquifies the metal, and pours it into moulds of sand. For the sake of lightness, and economy of material, many articles are made hollow ”

“ In the progress of the commerce, they would deal for nothing but metal; and, at length, brass was so eagerly sought for, in preference to iron, that, before the navigators quitted the place, scarcely a bit of brass was left in the ships, except what belonged to the different instruments. ”

“ One of the alloys most useful to the arts is brass; it is more ductile and less easily oxidised than even its copper constituent, notwithstanding the opposite nature of the zinc. This alloy may exist in many different proportions, under which it has different names, as tombac, similor, pinchbeck, &c. Copper and tin form, also, a compound of remarkable utility, known under the names of hard brass, for the bushes, steps, and bearings of the axles, arbours, and spindles in machinery; and of bronze, bell-metal, &c. ”

“ The brass is left in the solution until the required tint is produced. The color produced is uniform, black, and tenacious. The brass is rinsed and dried in sawdust. A great variety of effects may be produced by first finishing the brass before blackening, as the oxidizing process does not injure the texture of the metal. A satisfactory finish is produced by first rendering the surface of the brass matt, either by scratch-brush or similar methods, as the black finish thus produced by the copper solution is dead—one of the most pleasing effects of an oxidized surface. ”

“ Whether for speculum metal, bronze, or gun-metal, the metals must be mixed exactly, and for this purpose be kept a long time in fusion, and constantly stirred; otherwise, the alloy will not be of a uniform quality, as the greater part of [200] the copper will sink to the bottom, and the greater part of the tin rise to the surface. When we speak of brass guns, as that name is generally applied to them, we are to understand, that they are not made, like brass, of an alloy of copper and zinc. ”

“ We have no instrument that could do it, no composition that could make tools of temper sufficient to cut bass reliefs in granite or porphyry so readily; and our ignorance in this is the more completely shewn, in that we have all the reasons to believe, the cutting instrument with which they did these surprising feats was composed of brass; a metal of which, after a thousand experiments, no tool has ever been made that could serve the purpose of a common knife, though we are at the same time certain, it was of brass the ancients made their razors. ”

“ Some are so small and minute, although perfect in every detail, that it is difficult to understand how the worker in brass even if he had been a jeweller and accustomed to fashion the settings of small stones could so accurately have produced such tiny machines. It is said that the smallest engine in the world, a beautiful piece of metal-work, owned by an American collector, stands on a ten-cent piece! ”

“ If a tool having very much top slope is used for brass, there is danger of its gouging into the metal, especially if the part being turned is at all flexible. The clearance angle of a brass tool is usually about 12 or 14 degrees, which is 3 or 4 degrees greater than the clearance for steel turning tools. Most brass is easily turned, as compared with steel, and for that reason this increase in clearance is desirable, because it facilitates feeding the tool into the metal, especially when the carriage and cross-slide movements are being controlled by hand as when turning irregular shapes. ”

“ Would some ingenious man pursue these experiments, perhaps we might have needles made of brass to act as strongly as steel ones do, which would have the advantage of being less liable to rust at sea than steel ones are.
But my whole design was to shew, that brass is by no means a proper metal to make compass-boxes of, or to be employed in any instrument where magnetism is concerned. For as it is demonstrable, beyond all contradiction, that some brass is found endued with a power of attracting the magnetic needle ”

“ Wrought iron and mild steel are above all other metals suitable for tension joints where there is not continuous rapid motion. Where such motion occurs, a layer, or, as it is technically termed, a “bush,” of brass is inserted underneath the iron. The joint then possesses the high strength of a wrought-iron one and at the same time the good frictional qualities of a brass surface. Leakage past moving metal joints can be prevented by cutting the surfaces very accurately to fit each other. ”

“ Brass. —This well known alloy is made by mixing zinc with copper. There are twenty or more different kinds of brass but common brass is made of 36 parts of zinc and 64 parts of copper.
Brass is harder than copper and while it can be hammered and drawn it is not nearly as malleable or as ductile as copper. It can be sawed, drilled, threaded and machined easily and is about the best alloy you can use for making small parts of machines.
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Type-metal. —All kinds of metals shrink when they cool after being run into a mold and so the edges of the castings are never very sharp. ”

“ Brass-work, or any metal-work not lacquered, is cleaned by a little oil and rottenstone made into a paste, or with fine emery-powder and oil mixed in the same manner. A small portion of sal ammoniac, beat into a fine powder and moistened with soft water, rubbed over brass ornaments, and heated over a charcoal fire, and rubbed dry with bran or whitening, will give to brass-work the brilliancy of gold. In trimming moderator lamps, let the wick be cut evenly all round; as, if left higher in one place than it is in another, it will cause it to smoke and burn badly. ”

“ This metal can be reduced by forging to any shape; but, during the process, it will bear no heat greater than a red heat; and, as it does not admit of welding, like iron, different pieces are united with bolts, or rivets, of the same metal, as in the case of the larger kinds of vessels, or by means of solder made of brass and zinc, or zinc and lead, as in the case of those of smaller dimensions.
5. Brass is applied to a greater variety of purposes in the arts than copper. ”

“ Taking one of the square strips of brass we have seen in the cutting-mill, he hammers its end to a point on a small anvil at one side of him, and passes it through the eye of a huge needle fixed in the bench on the other side of him. He then seizes the point of the strip of metal with a great pair of pincers attached by a chain to the drum, puts his foot upon a treadle beneath him, and round goes the drum—the Giant in the rolling-mill turns it—dragging the pincers with it, and drawing the strip of metal slowly but surely through the round eye of the needle. ”

“ Brass, Gen. An alloy made by mixing copper with tin, or else with zinc or silver. Another name for it is Bronze (q.v.) . Corinthian brass is very celebrated, but little is known of its composition even at the present day. Mosaic gold, pinchbeck, prince’s metal, &c., are varieties of brass differing in the proportions of the ingredients. Brass beaten into very thin leaves is called Dutch Metal.
Fig. 101. Brassart.
Brassart. Plate armour for the arm. (Fig. 101.)
Brasses. Engraved metal plates inlaid in the pavements or walls of churches as monuments. ”

“ Every alloy is, in reference to the arts and manufactures, a new metal, on account of its chemical and physical properties. A vast field here remains to be explored. Not above sixty alloys have been studied by the chemists out of many hundred which may be made; and of these very few have yet been practically employed. Very slight modifications often constitute very valuable improvements upon metallic bodies. Thus, the brass most esteemed by turners at the lathe contains from two to three per cent. of lead; but such brass does not work well under the hammer ”

“ This is a process for joining metal parts, very similar to soldering, except that brass is used to make the joint in place of the lead and zinc alloys which form solder. Brazing must not be attempted on metals whose melting point is less than that of sheet brass. ”

“ In various rooms, by various machines, the work of perfecting the parts from the first blank form cut out of Connecticut brass goes on. Shades of size are adjusted by the friction of whirring cylinders coated with diamond dust. A flying steel point touched with diamond paste pierces the heart of the "jewels." Wheels rimmed with brass wisps hum steadily, as they frost the plates with sparkling gold. Shaving of metal peel off, as other edges turn, so impalpably fine that five thousand must be laid side by side to make an inch. ”

“ MODERN JAPANESE CLOISONNÉ ON METAL.
"The fine threads of brass that run through the surface give a very pretty appearance to the work, as they look like gold, and are perfectly even with the rest of what has been laid on to the original bowl. In some of the most expensive of the enamel-work the threads are of fine gold instead of brass; but there is no particular advantage in having them of gold, as the brass answers all purposes and the gold serves as a temptation to robbers. ”

“ The story was intended to teach all workers in brass and other metals, that they must be very patient, especially in annealing. Annealing oxidizes and softens the metal. While hammering cold sheet brass, the oft repeated blows harden the metal and cause brittleness. ”

“ If a cylindrical bar or thick tube of brass, six inches long, and about two inches in diameter, is attached to a wooden cylinder of the same size, the conducting powers of the two substances are well displayed by first straining a sheet of white paper over the brass, and then holding it in the flame of a spirit lamp. The heat being conducted rapidly away by the metal will not scorch the paper, until the whole arrives at a uniform high temperature ”