Page:On the economy of machinery and manufactures - Babbage - 1846.djvu/432

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398
ADDITIONS.
Table of the Prices and Weights of various ornaments of Berlin iron.
Articles. No. to cwt. Price of each.
s. d.
1. Diadems, 71/2 high by 51/4 broad 1100 17 4
2. Bracelets, 7 in. long by 2 in. broad, 72 pieces 2090 9 1
3. Collars, 18 in. long, 1s. 6d. from 37 to 40 single pieces 2310 6 5
4. Girdle buckles, 31/2 in. high, 21/4 broad 2640 2 8
5. Sevigné needles, 21/2 high by 11/2 broad, 11 pieces 9020 4 7
6. Sevigné earrings, 3 in. long, 7/8 broad, 24 pieces, pairs 10,450 5 5
7. Shirt buttons 88,440 0 6

The grey cast-iron used in this manufacture costs about 6s. 5d. per cwt.; therefore the labour bestowed on the material increases its value about 1100 times in the coarser, and nearly 10,000 times in the finer articles. The prices in this table are the retail prices in 1833. In 1827 they were about double, and in 1821 about triple those given above.

The causes of the perfection in this manufacture appears to depend partly on the skill of the moulders, partly on the excellence of the sand, but chiefly it seems to arise from the quality of the iron, which is melted at as low a temperature as possible. Now if this iron when fluid has, like water, a point of maximum density little above its point of solidifying, then if it is poured into a mould at this temperature, it will expand in cooling, and fill up the most minute