_ 194 E.. B. Andrews on a Seam of Coal. 
of not less than 25 or 80 feet. Over 2,000 flasks of mercury 
were thus recovered in a single year from the foundations of the 
two furnaces. This loss is entirely avoided by the improved 
construction which has been adopted. é 
The whole process of reduction is extremely simple, the time 
occupied from one charge to another being usually about seven 
d metal begins to run in from four to six hours after 
the fires are lighted, and in about sixty hours the process 18 
completed. e metal is conducted through various condensing 
chambers by means of pipes of iron, toa “crane-neck,” which 
discharges into capacious kettles. It undergoes no further pre 
paration for market, being quite clean from all dross. 
Deducting 24 years, during which the mines were in a state 
of inactivity, pending the decision of the law-suit, the average 
monthly product for 124 years has been not far from 2,500 flasks, 
of 764 each, of mercury. The selling price in San 
Francisco is, at present, and has been for some time past, 75c. 
per pound, while in London and New York it has ranged from 
40 to 50c. per pound. 
San Francisco, May, 1864, 
Arr. XIX.—Observations on a Seam of Coal; by Prof. E. B. 
ANDREWS, Marietta College, Ohio. 
THE seam of coal here described is located in the northern part 
of Washington Co., Ohio. It extends through the hills for several 
miles, and is generally of workable thickness. On Bear Creex, 
a small tributary of the Muskingum river, which latter stream 
of no other seam of coal of economic value above it in our Ohio 
_ rocks, although we find perhaps two hundred feet of unproduc 
tive sandstones and shales still higher. It is about sixty feet 
higher in the series than a peculiar group of limestone strata, 
with ee - — a seam of coal now worked at yer) 
a2 Run on the kingum river. This is very persistent, 
Pe and, after showing itself overa catsidarable dart of Washington 
