00 | 294.00
1.0 | 10888.89 | 6533.33 | 1633.33 | 653.33 | 326.67
------------+----------+----------+-----------+-----------+------------
When, as in this table, the fraction of an ounce is expressed by two
places of decimals, it may be reduced to pennyweights (dwts.) by
dividing by 5. For example, 0.40 of an ounce is 8 dwts. The fraction of
a dwt. similarly expressed may be converted into grains with sufficient
exactness by dividing by 4. Thus, 1.63 ozs. equal 1 oz. 12.60 dwts., or
1 oz. 12 dwts. 15 grains. In England it is usual to report in ounces and
decimals of an ounce.
The way to use the table is best shown by an example. Suppose a button
of silver weighing 0.0435 gram was obtained from 20 grams of ore. Look
down the 20-gram column of the table, and select the values
corresponding to each figure of the weight, thus:--
0.04 = 65.33 ozs. to the ton
0.003 = 4.90 "
0.0005 = 0.82 "
------ -----
0.0435 = 71.05 "
Add these together. The produce is 71.05 ozs., or 71 ozs. 1 dwt. to the
ton.
Or, suppose an ore is known to contain 1.24 per cent. of silver. Look
down the 100-gram column, select the values, and add them together as
before.
1.0 = 326.67 ozs. per ton
0.2 = 65.33 "
0.04 = 13.07 "
---- ------
1.
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