vals, will represent the mass from which it was taken. Taking a heap of ore, A, and selecting one out of every twenty spade-, bag-, barrow-, or wagon-fuls, according to the quantity of stuff in the heap, there is obtained a second heap, B, containing one-twentieth of the stuff of the heap A. If we crush the stuff in B until this heap contains approximately the same number of stones as A did--which means, crushing every stone in B into about twenty pieces--B will become the counterpart of A. Selecting in the same manner 5 per cent. of B, there is got a third heap, C. This alternate reduction and pulverising must be carried on until a sample of suitable size is obtained. This may be expressed very clearly thus:--
A = 1000 tons of rocks and lumpy ore. B = 50 " " rough stones, 1/20th of A. C = 2.5 " " small stones, 1/20th of B. D = 0.125 " " coarse powder, 1/20th of C.
[Illustration: FIG. 1.
PARTLY REDUCED CONE
PLAN OF FRUSTRUM DIVIDED.
ELEVATION OF FRUSTRUM DIVIDED.
Who Murdered Mr. Malone? Book 1 of the Garden G... Read more
After finding the body of a dragon in a metalli... Read more
*This is a stand-alone book in the Fearsome Ser... Read more
Fans of the Hunger Games and Sci-Fi Thrillers will... Read more
While rumors of monsters rising in the south bring... Read more
The list of books below is based on the weekly downloads by our users regardless of eReader device or file format.
See more popular titles from this genre.