| James Dwight Dana - 1850 - 800 pages
...generally only 7 or 8, and occasionally so little as 3 or 4 per cent of metal. In the Tatter case, such poverty of ore is only made up by its facility of...judged of by the color; if of a fine yellow hue, and readily yielding to the hammer, it may be considered a good ore ; but if hard, and pale-yellow, it... | |
| James Dwight Dana - 1851 - 458 pages
...generally only 7 or 8, and occasionally as little as 3 to 4 per cent, of metal. In the latter case such poverty of ore. is only made up by its facility of...fuel, or the convenience of smelting. Its richness may generally be judged of from the color : if of a fine yellow hue, and yielding readily to the hammer,... | |
| James Dwight Dana - 1854 - 858 pages
...Redruth rarely yielding 12, generally only 7 or 8, and occasionally but 8 or 4- per cent, of metal. Its richness may in general be judged of by the color ; if of a fine yellow hue, and readily yielding to the hammer, it may be considered a good ore; but if hard, and pale-yellow, it is... | |
| James Dwight Dana - 1854 - 954 pages
...generally only 7 or 8, and occasionally but 3 or 4 per cent. of metal. Its richness may in general bo judged of by the color; if of a fine yellow hue, and readily yielding to the hammer, it niny be considered a good ore; but it hard, and pale-yellow, it... | |
| J.D. Dana - 1855 - 440 pages
...generally only 7 or 8, and occasionally as little as 3 to 4 per cent, of metal. In the latter case such poverty of ore is only made up by its facility of...fuel, or the convenience of smelting. Its richness may generally be judged of from the color : if of a fine yellow hue, and yielding readily to the hammer,... | |
| James Dwight Dana - 1855 - 446 pages
...generally only 7 or 8, and occasionally as little as 3 to 4 per cent, of metal. In the latter case such poverty of ore is only made up by its facility of...fuel, or the convenience of smelting. Its richness may generally be judged of from the color : if of a fine yellow hue, and yielding readily to the hammer,... | |
| James Dwight Dana - 1857 - 458 pages
...generally only 7 or 8, and occasionally as little as 3 to 4 per cent, of metal. In the latter case such poverty of ore is only made up by its facility of...fuel, or the convenience of smelting. Its richness may generally be judged of from the color : if of a fine yellow hue, and yielding readily to the hammer,... | |
| James Dwight Dana - 1864 - 502 pages
...generally only 7 or 8, and occasionally as little as 3 to 4 per cent, of metal. In the latter case such poverty of ore is only made up by its facility of...fuel, or the convenience of smelting. Its richness may generally be judged of from the color: if of a fine yellow hue, and yielding readily to the hammer,... | |
| Henry Watts - 1864 - 1002 pages
...cent., generally only 7 or 8, and sometimes only 3 or 4 per cent, of copper. If of a fine yellow colour and yielding readily to the hammer, it may be considered a good ore ; but if hard and pale yellow, it is poor, from admixture of iron pyrites. The copper beds of Falü un in Sweden are... | |
| James Dwight Dana - 1866 - 466 pages
...or 8, and occasionally as little as 3^ to 4 per cent, of metal. In the latter case such poverty ff ore is only made up by its facility of transport,...the moderate expense of fuel, or the convenience of smeltinar Its richness may generally be judged of from the color : tf of a fine yellow hue, and yielding... | |
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