Type metal

“ The types cast by the type-founder are oblong square pieces of metal, each having, on one end of it, a letter or character, in relief. The metal of which these important instruments are composed, is commonly an alloy consisting principally of lead and antimony, in the proportion of about five parts of the former to one of the latter. ”

“ MOCK GOLD Fuse together 16 parts of copper, 7 of platinum, and 1 of zinc. When steel is alloyed with 1/500 part of platinum, or with 1/500 part of silver, it is rendered much harder, more malleable, and better adapted for all kinds of cutting instruments. Note.—In making alloys, care must be taken to have the more infusible metals melted first, and afterwards add the others.
151. BRITANNIA METAL Take 4 parts of brass, and 4 parts of tin; when fused add 4 parts of metallic bismuth, and 4 parts of metallic antimony. ”

“ 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. ”

“ Other metals employed are copper, brass, tin, zinc, phosphor-bronze, lead, antimony, bismuth, pewter, Muntz metal, aluminium, sodium, potassium, platinum, gold, silver, nickel, and a great variety of the bronzes, which are valuable compounds varying in tenacity and hardness from the hardest steel to that of soft copper. Most of the above are manufactured into wire, sheets, tubes, rods, &c., and can in addition be cast into any form from a crucible. Copper can be forged but not welded; joints in it are generally brazed or soldered. ”

“ When two metals come together in a molten state, they often form, not a mixture of the two, part copper and part tin, for example, but a new compound, different from either, called an alloy. Copper is, so to speak, a sociable metal, and readily unites with many different metals—amongst others with tin, when it forms bronze, the article that marks a new state in the history of primitive culture. It seems to us strange that an alloy, a combination of two different metals, should have been the first used by man, and not a simple metal like iron. ”

“ The different metals are malleable, ductile and tenacious in the following order; white metal or britannia, aluminum, zinc, copper, low brass, high brass, German silver, steel, tin plate. White metal does not harden in spinning, but it requires special skill in handling, or the metal will be of very uneven gage. The best metal for an amateur to start on is copper, as it is both tenacious and ductile, and will stand much abuse in the fire and on the lathe. ”

“ Gold may be separated by fusion, from every addition of Copper, Tin, Iron, Lead, Orpiment, Antimony, Arsenick or the like, and be purifyed without Cupels, each being kept apart; profitable for Metallurgists and the like, from the shortness of the time, smallness of the charge and labour, and much gain.
Every imperfect metal without the mixture of other metals, may be ripened by this secret alone in the fire, in the space of an hour, so that it will yield Gold and Silver, but without gain. ”

“ Very few metals are used alone in the various arts and manufactures. For every purpose some combination has been found which makes the product better. Even coins are so alloyed. Silver and gold in the form of money would be entirely too soft, unless alloyed with some hardening metal. Some substances, like arsenic, antimony and bismuth, are too brittle to be used alone. The only metals which can be used alone are aluminum, zinc, iron, tin, copper, lead, mercury, silver, gold and platinum."
"What is bronze, of which all the ancient guns were made?" ”

“ Gold is rarely employed in a state of perfect purity, but is generally used in combination with some other metal, which renders it harder, and consequently more capable of enduring the friction to which it is exposed. The metal used for this purpose is called an alloy, and generally consists of silver or copper. ”

“ Man then began to make weapons and implements of metal, and found them better than the weapons of stone. We may infer this from the fact that the stone implements, of sharp and shapen flint, become less numerous as we come to higher strata, or layers, in the ground, and the metal implements are more numerous.
The metal of which the earliest metal implements were made is either pure copper or bronze, which is a mixture of copper and tin. Copper is not a very hard metal. ”

“ Metal itself implied metal-working; and metal-working brought about, not only the arts of smelting and casting, but also endless incidental arts of design and decoration. The bronze hatchets, for example, to take our typical implement, begin by being mere copies of the stone originals; but, as time goes on, they acquire rapidly innumerable improvements. First, metal is economized in the upper part which fits into the handle, while the lower or cutting edge is widened out sideways, so as to form an elegant and gracefully curved outline for the whole implement. ”

“ Power Presses in Metal Working.
From glass let us now turn to metals. It is their tenacity that chiefly gives them value; this tenacity is usually accompanied by a hardness which disposes us to regard nickel, for example, as of a solidity quite unyielding. But the coins in our pockets prove that under the pressure of minting machinery they are as impressible as wax. In molds and dies, each the counterpart of the other, brass, bronze, iron, steel, and tin-plate take desired forms as readily as if paste. Solid though these metals appear they yield under severe stress with a semi-fluid quality. ”

“ Gold and silver, in their pure state, are too soft and flexible to form either vessels or coins of sufficient strength and durability; but when alloyed with a little copper, they acquire the requisite hardness and stiffness for these and other purposes.
When we have occasion to unite several pieces of the same or of different metals, we employ the process called soldering, which consists in fixing together the surfaces by means of an interposed alloy, which must be necessarily more fusible than the metal or metals to be joined. ”

“ The chief alloys, or compound metals in use, are, brass, made of copper and zinc; pewter, made of lead and tin; bell metal and gun metal, made of copper and tin; and solder, which is a kind of pewter, and made of the same metals; the silvering for looking-glasses is made of mercury and tin; the gold and silver used for coin are not pure metals, but alloyed with two parts of silver or copper to every twenty-two of the pure metal, and this forms the “standard” gold or silver. ”

“ In such primitive furnaces the well known and soft metals would naturally be worked first, and afterward copper, tin, and iron would be obtained from their ores. A variety of substances that occur together in nature would be smelted together in mixtures, and different metals would naturally be mixed and a great variety of products obtained.
CHARACTERISTICS OF COPPER ALLOYS.
The oldest civilized races used bronze for a long space of time as their chief useful metal, although some neighboring races understood the metallurgy of iron. ”

“ Hence arises the superiority of this metal for making mechanics’ instruments or tools, by which all other metals, and even itself, are filed, drilled and cut. The various degrees of hardness given to iron, depend on the quantity of ignition it possesses at the moment of being tempered, which is manifested by the succession of color exhibited on the surface of the metal, in the progress of its receiving the increasing heat. These are, the yellowish white, yellow, gold-color, purple, violet, and deep blue; after the exhibition of which the complete ignition takes place. ”

“ The exciting arch may be constructed with two or three metals, or even one metal only; with alloys, amalgams, or other metallic or mineral combinations, carbonated substances, &c. It is observed, that metals, which are in general the most powerful exciters, induce contractions so much the more as they have an extent of surface. Metals are all more or less excitants; and it has been noticed that zinc, gold, silver, and pewter, are of the highest rank; then copper, lead, nickel, antimony, &c. ”

“ The metallic alloy should also be occasionally stirred up with a rod of pottery ware.
The most direct evidence of a chemical change having been effected in alloys is, when the compound melts at a lower temperature than the mean of its ingredients. Iron, which is nearly infusible, acquires almost the fusibility of gold when alloyed with this precious metal. The analogy is here strong with the increase of solubility which salts acquire by mixture, as is exemplified in the difficulty of crystallising residuums of saline solutions, or mother waters, as they are called. ”

“ II.—An invention, patented in Germany, covers a metallic alloy, to take the place of gold, which, even if exposed for some time to the action of ammoniacal and acid vapors, does not oxidize or lose its gold color. It can be rolled and worked like gold and has the appearance of genuine gold without containing the slightest admixture of that metal. The alloy consists of copper and antimony in the approximate ratio of 100 to 6, and is produced by adding to molten copper, as soon as it has reached a certain degree of heat, the said percentage of antimony. ”

“ The metals thus united may be either the same or dissimilar; but the uniting metal must always have an affinity for both. Solders must be, therefore, selected in reference to their appropriate metals. Thus tin-plates are soldered with an alloy consisting of from 1 to 2 parts of tin, with 1 of lead; pewter is soldered with a more fusible alloy, containing a certain proportion of bismuth added to the lead and tin; iron, copper, and brass are soldered with spelter, an alloy of zinc and copper, in nearly equal parts ”

“ As you know, most of the metals have chums or affinities with other substances, just as gold has with mercury. These chums of the metals were also in that molten ocean, but not always in the same proportions, nor yet distributed regularly. So metallic compounds were formed at different times and in diverse places. These compounds had varying densities, with the result that in later ages they behaved in a way quite different from the pure metal. You see, Jim, long before the crust of the earth was even formed, gold was scattered far and wide, and already was in different forms. ”

“ If, without any reference to history, we should seek to determine which of the two metals, copper or iron, was first discovered and used for weapons and tools, we should very readily come to a conclusion in favour of that which is most easily recognised as a metal when in the earth. ”

“ We have, secondly, work in bronze, iron, gold, and [Pg 97] other metals; in which the laws of structure are still more definite.
All kinds of twisted and wreathen work on every scale become delightful when wrought in ductile or tenacious metal; but metal which is to be hammered into form separates itself into two great divisions—solid, and flat.
a. In solid metal-work, i.e., metal cast thick enough to resist bending, whether it be hollow or not, violent and various projection may be admitted, which would be offensive in marble ”

“ These local accumulations of ores first made it possible for men to obtain the rarer metals in masses and apply them to use. The metallic sulphurets nearer to the surface have been changed by atmospheric action partly into the simple metals, partly into oxides. This was a fact of great importance in the beginnings of metallurgic art; for the oxides are much easier to reduce to the condition of pure metal than the sulphurets. The unmixed metals—the precious metals and copper—are, of course, immediately available, and can be brought into any form that may be desired by hammering or casting. ”

“ Castings in bell metal are all more or less brittle; and, when recent, have a color varying from a dark ash-gray to grayish-white, which is darkest in the more cuprous varieties, in which it turns somewhat on the yellowish-red or bluish-red. The larger the proportion of copper in the alloy, the deeper and graver the tone of the bells formed of it. The addition of tin, iron, or zinc, causes them to give out their tones sharper. Bismuth and lead are also often used to modify the tone, which each metal affects differently. ”

“ But when the current was passed through the spiral wire in this vacuum a peculiar change took place in the platinum itself. The gases retained in the pores of the metal at once escaped, and the wire took on such peculiar physical properties that it was supposed for a time by some physicists that a new metal had been produced. The metal acquired a very high degree of elasticity and became susceptible of a high polish like silver, at the same time becoming almost as hard as steel. ”

“ After the lead is put into the cupel, it gets immediately covered with a coat of oxide, which resists the admission of the silver to be assayed into the melted metal; so that the alloy cannot form. When a bit of silver is laid on a lead bath in this predicament, we see it swim about for a long time without dissolving. In order to avoid this result, the silver is wrapped up in a bit of paper; and the carburetted hydrogen generated by its combustion, reduces the film of the lead oxide, gives the bath immediately a bright metallic lustre, and enables the two metals readily to combine. ”