Page:The New International Encyclopædia 1st ed. v. 13.djvu/642

MINT. 572 of not more tlian five cents an ounce being made for assaying and iflining. I'oi' the silver alloy in the gold the owner will k paid either in silver bars or silver dollars, at the market value of silver. If the gold or silver is to be coined into money the pure bars must be mixed with cop- per alloy; standard gold coin is composed of 75 parts of'copper and 2'i of silver in 1000. The law allows a slight variation from this standanl, hut in actual practice a single gold coin rarely varies more than 0.03 per cent, from the standard, either way, and a silver coin, which is much more diflieult to manage, not more than 0.1 per cent., while the average is almost exactly correct. Weighed quantities of gold and copper, or of silver and copper, are melted together in a black-lead crucible, the molten metals thoroughly stirred together, and then poured into cast-iron molds to form ingots. These vary in size ac- cording to the denomination of the coins to be made frcmi them. The following table, compiled by William E. Morgan, Coiner of the United States Mint at Philadelphia, gives the sizes and approximate weights of .yold ingots: MINT. while t'liose that are above weight are filed down. The standard weight for gold coins is as follows: Double eagle, 51(i grains; tolerance allowed by law, 0.50 grain. Eagle, ,258 grains; tolerance, 0.50 grain. Half eagle, 129 grains; tolerance, 0.25 grain. Quarter eagle, 54.5 grains; toler- ance, 0.25 grain. Next comes the process of milling, or produc- ing a raised rim around the edge of the coin, to prevent abrasion. This is accomplished in a milling machine, into which tlic blanks are placed one by one by hand. The blanks rotate in a hori- zontal plane in a groove formed on one side by a revolving wheel and on the other by a fixed segment of corresponding groove. Each piece, as it passes through this narrow groove, has its edges forced up into an even rim. After an ncaling and cleaning, the coins are now read for the final process of stamping. The planchet, fed to the press through a vertical tube, is automatically placed in a steel collar, whose inner surface is reeded to produce the fluted surface on the milled edge of the coin. Here it is firmly held while the dies close upon it with enormous force, producing impressions on DEXOMINATIONS Double eagles... Eaales Half eagles Quarter eagles.. Approximate weight iu ounces 80 B2 40 33 Len^h in inches 12% 12 12V4 Thickness in inches' Width in inches H4 % H The ingot for silver dollar coinage is 1% inches wide, 'A inch thick, and I2V2 inches long. The ingots are passed repeatedly between heavy rollers to form them into stri|>s, a process which is called 'breaking down.' After each passage the rollers are screwed tighter, the amount of pressure being regulated exactly by a clock-dial. The strips are annealed during the process to prevent their breaking. The strips, having been greased with tallow, arc finally reduced to stand- ard thickness by drawing out in draw-benches by a process similar to that of wire-drawing. (See Wire.) Having been drawn to the required weight, which is ascertained by weighing sample blanks cut from each end, the strips are cut into planehets. by means of a steel punch, working into a matrix. (See Die.s and Die-Sixkixg.) These planehets are now cleaned and carefully sorted, all that are not perfect or are under the standard weight being set aside to be remelted, both sides of the coin. (This process and the preparatory one of engraving and stamping the dies are described under DiKs axd DieSi.xking,) The pressure required to prodicc a clear, s!. irp impression on the various gold coins is as fol- lows: Double eagle, 175 tons; eagle, 120 tons; half eagle, 75 tons ; quarter eagle, 40 tons. Double eagles and eagles are struck at an average rate of 80 per minute; half eagles and quarter eagles at a rate of 100 per minute. The pressure required for stamping silver coins is: Dollar, 150 tons; half dollar, 110 tons; quarter dollar, 80 tons; dime, 40 tons. The first three are struck at an average rate of 80 per minute, and dimes at the rate of 100 per minute. The total coinage of gold bv the mints of the Inited States from 1702 to .hine 30. 1900, was .$2.1(!7,0S8,1I3, of which it is estimated that $923,053,(142 is still in existence as coin in the United States, while the remainder represents COINAOE OF SlLTBR COINS, BY ACTS AN1> DENOMINATIONS, FROM 1792 TO .IrXE 30, 1900 (From Circular No. 113, issued b.v the Cnlted States Treasur.v Department. July 2, 1900) DCNOMINATION 1792 to 1863 1863 to Feb. 12, 1873 Feb. 12. 1873. to .lune 30. 1900 Total silver 2.506,890.00 5.624.348.00 498.496.215.00 3,'>,96'>,924.00 60.000.00 506 527.4.'i;V0O Trade dollars 35.»«5.W4.(X) 60.QUO.tl0 2.506.S90.00 5.624.348.00 6.')4,612,139.00 542.543,377.00 66.280,640.50 32,666,832.60 4C.041.re!6,lKI 2..Mll.().i2..'iO 41,880,190.60 10.006.76 271.000.00 27.133.111.10 H-1,08S..'.(I!I.(MI Half dollarrt Columbian a.i'iOl ,0,12.5(1 Quarter dollars 3,994,640,56 17,879,790.60 C3.7fi:).021..'«l Quarter dollars. Cnlumbian lO.OO.'i.T,') 27I,«I0(«) 3,890,230.10 1,826,126.40 744,927.00 4.908,520.00 3,056,093.00 5.'17,160.20 35,931.861.20 Hal( dimes . . . . . 4.K80.21V.40 1.282,087.20 Total subsidiarr 76.734.964.60 5».(HT.396,30 117.845.39.'5 85 263,627.7e«.M Total Bilvor 79.241.854.60 64.571,744.20 662.357.534.85 796.171.183.65