Free and Discounted Ebooks
Join 150,000 readers! Get our ebook deals straight to your inbox.

A Textbook of Assaying

For the Use of Those Connected with Mines

Cover image for

Download


Published: 1904
Language: English
Wordcount: 198,611 / 646 pg
Flesch-Kincaid Reading Ease: 72.7
LoC Categories: TN, LT
Downloads: 461
Added to site: 2006.07.04
mnybks.net#: 14001
Origin: gutenberg.org
Genre: Instructional
Excerpt

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.

CONE

PARTLY REDUCED CONE

PLAN OF FRUSTRUM DIVIDED.

ELEVATION OF FRUSTRUM DIVIDED.

SUBSCRIBE TO MANYBOOKS 

FREE EBOOKS 

Join 150,000+ fellow readers! Get Free eBooks and book bargains from ManyBooks in your inbox. 

We respect your email privacy

(advanced)
login | register

User ID

Password

reset password

Author of the Day

Vickie M McKeehan
If there are two things that Vickie McKeehan knows very well its romance and suspense. However, she doesn’t just love reading these type of books, but has also written numerous ones. Judging by the consistency at which her novels appear on Amazon’s Top 100 lists for these genres she also has a knack for creating characters who readers can identify with. Today we talk to Vickie about the first book in her The Evil Secrets trilogy, her journey as an author and what inspires her.
Read full interview...