i88 5 .] 
Analyses of Books. 
2 37 
Mr. R. Bruce Foote contributes notes on the distridl: between 
the Singarem Coal-field and the Kistna River. He mentions a 
ec of iron ore of very rich quality situate at the distance of half 
a mile from the southern boundary of the Singareni Coal-field 
and near the great limestone beds of Kadapa a°- e . 
Concerning the diamond deposits along the left bank of the 
Kistna, the author is of opinion that this industry is “ crushed by 
the heavy royalty levied and by other absurd restrictions imposed 
by certain people at court in Hyderabad.” He adds that “ there 
is certainly no geological reason why the undisturbed gravels 
should not be as rich in diamonds as the portions of the same 
beds explored in past times. 
Mr. D. La Touche furnishes a note on coal and limestone in 
the Doigi ung River, Assam. He finds the coal, — at least the 
sample taken at the outcrop,— very poor in quality, yielding on 
analysis 4876 per cent of ash anti only 15-10 per cent of feed 
carbon. I he limestone he thinks sufficient to supply the wants 
W.T.BUHfoni F.R.3., gives a paper on “ Homotaxis, 
as illustrated from Indian Formations,” being a reprint of his 
address as President of the Geological Sedtion of the British 
Association, at Montreal. 
Second Annual Report of the United States Geological Survey to 
the Secretary of the Interior, 1880-81. By J. W Powell 
Washington : Government Printing Office. 
In this goodly volume we find, among much other interesting 
m atter, an account of the heat-phenomena of the Comstock Lode. 
Tne mere fadt is well known to all persons interested in Geology* 
but the explanation is still wanting. It appears that the wafer 
which flooded the lower levels of the Gold Hill mines during the 
past winter had a temperature of 170° F. “This water will cook 
food and will destroy the human epidermis, so that partial immer- 
sion in it is certain death. In spite of ventilation carried out 
to an extent without precedent elsewhere deaths from mere heat 
aie not uncommon. The air in most parts is very nearly satu- 
rated with moisture, and it is very questionable whether it will be" 
possible to push the workings much further down. Depth and 
temperature seem proportionate, setting aside local divergences 
and it would hence seem that the source of heat must lie far below 
the greatest depth as yet reached, i.e., above 2000 feet. It is 
calculated that at the depth of 5000 feet boiling water would be 
reached, whilst in another hot mine, the Rosebridge Colliery 
water will not boil above 10,000 feet. & y ’ 
The two theories generally proposed to account for this ex- 
