262 
Siltrian,) as well as the Oriskany (the lower member of the 
Devonian) are both absent; and the Salina rocks are there 
many hundred feet thick, it seem probable that this latter 
group produces the gas there. This consideration points to 
another belt of gas wells that may be opened across New 
York, further north than the geological latitude of the 
Bloomfield well. Without maps it is difficult to make this 
subject clear, and I can but sum up by stating the proba- 
bility that across the State of New York, from east to west, at 
least three belts of gas wells will be obtained, and that special 
success will be dependent chiefly on the selection of points 
for boring where the three gas-charged horizons, the Salina, 
Marcellus and Genesee, lie some 500 feet and upwards in 
depth. Nearer the outcrops, where the depth is less, the 
pressure must have been reduced by leakage, in the shape of 
gas springs, so common in this range of country. Still there 
is no reason why, in many places where the spontaneous 
flow is sluggish, great volumes should not be obtained by 
the application of exhausters to tubed wells, such exhausters 
being operated, as I have further to propose, by Hugon Gas- 
engines supplied with a portion of the gas itself. Torpedoes, 
also, will no doubt find useful application in this connection. 
Dr. Stevens believes the Subcarboniferous also to be some- 
times gas-producing, and that the Venango county gas wells 
were from Upper Devonian, or the Chemung and Portage, an 
opinion, which we have heard also from Dr. Newberry. In 
Canada, at Petrolia and elsewhere, according to Sterry Hunt, 
the chief gas and petroleum-bearing rocks belong to the 
Corniferous. 
So that we have here, widely spread over the immense 
area of the Devonian and Silurian basin of the Great Lakes 
and the Mississippi Valley, no less than five, probably six, 
beds of rock indicated, which, wherever lying deep enough, 
and thick and porous enough, will be found to pour out 
combustible gas when tapped, in the bountiful and apparent- 
ly exhaustless way we have seen. I believe, then, that I am 
fully justified in the editorial dictum indulged by me long 
since, in the AMERICAN GaAs-LIGHT JOURNAL, that: 
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