MECHANICS AND USEFUL ARTS. 75 



result : carbon, 68 per cent. ; oxygen, 18 ; water, 16 ; and ash 3.68 

 percent. It also contains ammonia, acetate of lime, fixed and 

 volatile oils. The deeper the peat found, the richer is it in car- 

 bon, and there are portions of the bog which will yield 70 to 75 

 per cent, of carbon. The average amount of carbon, thus far as- 

 certained by analysis of the various peat bogs of the United States, 

 equals 50 per cent." 



HEAT IN MENES. 



The "Virginia City (Nev.) Enterprise" says: "The increase 

 in the heat of our mines is now beginning to give many of our 

 mining companies more trouble, and is proving a greater obstacle 

 to mining operations in those levels lying below a depth of 1,000 

 feet, than any veins or 'pocket' deposits of water yet en- 

 countered. A number of the leading companies on the Comstock 

 are now engaged in putting in engines to be used expressly for 

 drivin<r fans for furnishing air to the lower levels, forcing it 

 through large tubes of galvanized iron. With this great in- 

 crease of heat in our mines comes a great decrease of water ; in 

 fact, in our deepest mine — the Bullion, which has attained the 

 depth of 1,200 feet — not a drop of water is to be seen; it is as 

 dry as a lime-kiln and as hot as an oven. 



'* In the lower workings of the Chollar-Potosi mine, which are 

 at a perpendicular depth of 1,100 feet below the surface, the ther- 

 mometer now stands at 100 degrees, — a frightful heat to be en- 

 dured by a human being engaged in a kind of labor calling for 

 severe muscular exertion. Here, also, we find the water to have 

 decreased till there is at the present time a very insignificant 

 amount, it being necessary to run the pump but 4 hours out of 

 the 24. 



" We misrht give other instances illustrative and corroborative 

 of what we have stated, but deem the evidence aft'orded by two 

 of our deepest mines, situated some considerable distance apart, 

 sufficient. Does it not appear likely, judging from the present 

 situation in the deepest levels of our mines, that the great Sutro 

 tunnel, if ever constructed, is more likely to be found useful as a 

 means of entrance for fresh air than of exit for water? The 

 * situation,' if we may so call it, so changes in our mines that we 

 hardly know one month ahead what would be of advantage to 

 us. Some months since we supposed we were to be drowned out 

 of the lower levels of our mines, or rather prevented from ever 

 attaining any very great depth, by a tremendous influx of water. 

 Now we find no water at all — or at best a trifling quantity — but 

 in its place hot air. No doubt this is a change for the better. It 

 will be much easier to force a column of light and' elastic air 1,000 

 feet downward than to lift a column of water the same dis- 

 tance. 



*' Should it prove a fact, as now seems probable, that the water 

 in our mines is confined to certain strata at no great depth from 

 the surface, sa}- between the depths of 400 and 900 feet, and sliould 

 it be found practicable to ventilate the deep workings of our 



