.... 1.1468 -----
------- -------
Totals 64.8585 789,694

"64.8585 grammes are almost exactly 1,000 grains, and 1 cubic foot of
this gas will weigh 267.9 grains; then the 100 liters, or 64.8585
grammes, or 1,000 grains, are 3,761 cubic feet; 3,761 cubic feet of this
gas contains 789,694 heat units, and 1,000 cubic feet will contain
210,069,604 heat units. Now, 1,000 cubic feet of this gas will weigh
265,887 grains, or in round numbers 38 lb. avoirdupois. We find that
64.8585 grammes, or 1,000 grains, of carbon contain 523,046 heat units,
and 265,887 grains, or 38 lb., of carbon contain 139,398,896 heat units.
Then 57.25 lb. of carbon contain the same number of heat units as 1,000
cubic feet of the natural gas, viz., 210,069,604. Now, if we say that
coke contains in round numbers 90 per cent. carbon, then we will have
62.97 lb. of coke, equal in heat units to 1,000 cubic feet of natural
gas. Then, if a ton of coke, or 2,000 lb., cost 10s., 62.97 lb. will cost
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