Calculated. Actual. Hydrogen...................... 47.09 42.09 Methane....................... 5.48 11.27 Olefines...................... 2.53 7.59 Ethane........................ 2.17 6.32 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 it from 16 to 17.5 candle power. When this is done by cannel, the cost is 2.6 pence per candle power, so that the extra 11/2 would cost 4d. per 1,000. Carbureting by the vapors of gasoline by the Maxim-Clarke process costs 13/4d. per 1,000, so that the extra candle power would mean an expenditure of 2.62 d. Unfortunately I have no figures upon which to calculate the cost of producing such a gas by the Dinsmore process, but with the three important water gas enrichers we can deal. Using Russian fuel oil, which can be obtained in bulk in London at 3d. per gallon, the proprietors of the Springer plant guarantee 51/2 candle power per 1,000 cubic feet of gas per gallon used, so that, to produce a 22 candle gas, 4 gallons would be used. The cost per 1,000 cubic feet may be roughly tabulated, as the coke used amounts to about 40 lb.