1879.] on Coining Silver into Rupees. 63 
Hence it will be seen that about 44 per cent. alone of the weight is 
unaccounted for at once, and that, after the particles are all recovered, the 
amount left in the drosses is about 6 parts in 10,000, and this includes the 
alloy burnt away. At the rate of 13 per cent. on the free copper, the loss 
on that metal would have been 607°2 tolahs, leaving only 126°6 tolahs 
or 0:010169 per cent. of the value as a real loss, but what is shown above 
fairly represents the experience of some years as regards the net loss of 
weight by burning. 
When passed by the test of assay, the ingots go to the Laminating 
Department, and from this time no trustworthy valuation can be made till 
the coin is ready for issue. Inall the succeeding processes metal is lost by 
abrasion and by alloy being burnt in the annealing processes and removed in 
the pickling necessary to clean the surface of the silver for stamping. On 
the other hand, oil and grease from the machinery adhere to the surfaces and 
(till the blanks are cleaned) a small portion of oxide adheres and thus the 
weight is increased. 
It will be seen from the following table that the Laminators cut off 
and reject about 2 per cent. of the metal received, and that, very little 
weight being apparently lost, the outturn of good blanks is nearly 60 per 
cent. of the weight ofingots. Good blanks here of course meaning those 
which are perfect in form and ready to be tested as to their sufficiency in 
weight. When the whole sweeps have been refined and the silver in them re- 
covered, there is ordinarily a gain in the Laminating Department from the 
causes I have spoken of. It appears that in a mean of several years the result 
of crediting the recoveries of sweep &e., has been a small gain in weight 
in these Departments, amounting to 000003 of the amount. It is here that 
the effect of bad silver is mainly felt : when silver which is derived from orna- 
ments, and a few other sources, is used without being well refined, the floors 
of the laminating rooms are covered with spangles, causing of course 
a heavy loss, and the edges of the straps are ragged, so that the outturn 
of blanks is much less than the normal amount, while the weight of 
scissel is sensibly increased. 
