Carbon monoxide............... 30.07 18.65
Carbon dioxide................ 3.78 2.32
Oxygen........................ 0.56 0.17
Nitrogen...................... 7.17 8.25
Sulphureted hydrogen.......... 1.15 2.84
------ ------
100.00 100.00

Showing how great the effect is of the diluents in the water gas in
preventing the overcracking of the hydrocarbons, as shown by the
increase in the percentage of them present in the finished gas; while
the enormous reduction in the amount of carbon monoxide present is due
to the interaction between it and the paraffin hydrocarbons in the
presence of red-hot carbon, a point which makes the Van Steenbergh
apparatus enormously superior to any of the superheater forms of
plant.

After all said and done, however, the reactions taking place, although
they have an intense fascination for the chemist, are not the factors
which the gas manager deems the most important, the cost of any given
process being the test by which it must stand or fall; and it will be
well now to consider, as far as it is possible, the expense of
enriching coal gas by the various methods I have brought before you.

In order to be well above the prescribed limit of illuminating power
at all parts of an extended service, the gas at the works must be sent
out at an illuminating power of 17.5 candles and we may, I think,
fairly take it that 16 candle coal gas, as made by the big London
companies, costs, as nearly as can be, 1s. per 1,000 cubic feet in the
holder, and the question we have now to solve is the cost of enriching