4d., or 1,000 cubic feet of gas is worth 4d. for its heating power. We
will now compare the heating power of this gas with bituminous coal,
taking as a basis a coal slightly above the general average of the
Pittsburg coal, viz.:

Per cent.
Carbon................................... 82.75
Hydrogen................................. 5.31
Nitrogen................................. 1.04
Oxygen................................... 4.64
Ash...................................... 5.31
Sulphur.................................. 0.95

"We find that 38 lb. of this coal contains 146,903,820 heat units. The
64.4 lb. of this coal contains 210,069,640 heat units, or 54.4 lb. of
coal is equal in its heating power to 1,000 cubic feet of natural gas. If
our coal cost us 5s. per ton of 2,000 lb., then 54.4 lb. costs 1.632d.,
and 1,000 cubic feet of gas is worth for its heat units 1.632d. As the
price of coal increases or decreases, the value of the gas will naturally
vary in like proportions. Thus, with the price of coal at 10s. per ton
the gas will be worth 3.264d. per 1,000 cubic feet. If 54.4 lb. of coal
is equal to 1,000 cubic feet of gas, then one ton, or 2,000 lb., is equal
to 36,764 cubic feet, or 2,240 lb. of coal is equal to 40,768 cubic feet
of natural gas. If we compare this gas with anthracite coal, we find that
1,000 cubic feet of gas is equal to 58.4 lb. of this coal, and 2,000 lb.
of coal is equal to 34,246 cubic feet of natural gas. Then, if this coal
cost 26s. per ton, 1,000 cubic feet of natural gas is worth 9½d. for its
heating power. In collecting samples of this gas I have noticed some very
interesting deposits from the wells. Thus, in one well the pipe was
nearly filled up with a soft grayish-white material, which proved on