Arizona silver belt., 1890-07-05
Testing Uncle SaM's Coins.
[From the Washington Star. l

|
 You would be amused to sec the sIl- | yer dollars that compose the stock of the Government assayer at the Treas ury building. Each one of them is i about foot long, of 2 narrow oval shape, and perforated with hundreds of little round holes. Such IS the form they appear Tn after being rolled out thin and punched with machine, All the silver coins that come to the department for testing are treated in this way 10 begin with. They are sent in from the mlnts as specimens, taken at random from every fresh lot made, and it i. the duty of the assayer to find ont whether these samples are of the weight and fneness required by law. Tbe weight is merely matter
 of a moments trial on scales, which
 are of such wonderful delicaey that a
 single hair an inch in length will al-
 together overcome the equipoise, but
 to discover the degree of fnensss
 which means the proportion of pure
 silver in the coin, is more difficult
 affair. It is decreed that the dollar, fer instance, must be exactly nine
 tenths silver, the remaining tenth be- ing copper, and yariatron of not mere than one and ons-haif grains in the quantity of the noble metal IS allowed.
 Tho silver dollar has to be rolled
 out thin in machine to begin with, because when tho coin Is made the
 silver in 1t has a tendency to go
 toward the middle, so that the metal on tho outside is not SC fine as wlinln.
 But the assayer must discover the
 average hneness of the piece in order to ascertain just how much silver
 is altogether m 1t, and te does this in
 very curious way. He passes tue l thin strip of metal into winch the dol
 lar has been rolled through little contriyance operated by crank that is turned by the hand The strip
 comes out punched as full of holes as
 it can be. while hundreds of small clr-
 eular disks about the sIze of gold
 quarter dollar fall out of the holes
 thus made into q llny box belsw.
 Next the disks arc taken out of the
 drawer and mixed np; few of them
 are taken from The lot and they, rep
 reSenting tbe average of silver, are
 subject te chemical snaiysls. The Director of the Aint.is charged with ] the cons he receives from the minis
 for testing in this way, and he sells back to the hints the perforated strips
 and disks. thus squaring that account, It is the samo with halves and quar-
 ters and dimes as witb dollars. But
 these subsidiary csps are not ss much
 in proportion to their legal-tender
 value as the dollar Two silver halves
 are worth about 5c less than one sil- yer dsllar. four quarters likewise and ten dimes the same way. The Cor ernmont makes about 25 per cent on all the money it coins ID silver, through the fact that there is hot 2 value oi
 silver in tbo coin. eqnal to what they pretend to be worth.
 Gold coins, however, aTo worth tbei full face yalre in gold, without coant' ing the one.tenth part of the copper they contain. The yellow metal, m. like the silver, does not aggregate in the middle of the piece. Therefore il
 IS not necessary to perforate geld coins for testing them. They are simpl. . rolled out each strip cut into three ! strips, and llttle pieces for chemica analysis are shipped of the cut edges . There IS a very snail amount of silye' I left in the gold piaces, as they ar' i made at the hints, and for the sake 0 arriving at perfect accuracy, the as $ sayer takes thus out by boiling II 0 nitric acid. The silver and gold sem . back to the mlnts for sale are melted > up by the quantity III big pot.