By the Silver Coinage Act (10 Geo. 5), the fineness of the British coinage was reduced on account of the increased price of silver bullion; and the silver coinage now consists of one-half silver, one-half alloy, one troy pound of silver being coined into sixty-six shillings. The copper which composes the alloy in the silver coinage hardens the material employed, and it is found to wear better.
In order to make the matter as simple as possible, we purpose giving a few practical alloys, as follows:—
Old standard silver alloy, cost 4s. 4d. per oz.
| oz. | dwts. | grs. | |
| Fine Silver | 0 | 18 | 12 |
| Shot Copper | 0 | 1 | 12 |
| 1 | 0 | 0 |
If it is intended that the above alloy should be for Hall-marking, it will be advisable to add a little extra silver to the prepared composition, because fine silver purchased from the refiner or bullion dealer is never absolutely pure, consequently the work will not pass the Hall; or better still alloy as follows:—
Old standard silver for Hall marking.
| oz. | dwts. | grs. | |
| Fine Silver | 0 | 18 | 14 |
| Shot Copper | 0 | 1 | 10 |
| 1 | 0 | 0 |
The new standard silver is composed of 38-1/3-40ths of fine silver and 1-2/3-40ths of copper alloy; or millesimal fineness 959 parts of fine silver and 41 parts of copper per 1,000 parts; the remedy being as before 0·004 parts.
New standard silver alloy, cost 4s. 6d. per oz.