| Coke, 100 chaldron, at £ 1. 7s. the chaldron | £ 135 | 0 | 0 |
| Breeze, or small coke, 3 chaldron, at 18s. the chaldron | 2 | 14 | 0 |
| Coal tar, 6 Tons, 8 Cwt. at £ 6. the ton | 38 | 8 | 0 |
| Ammoniacal liquor, 1536 gallons, at 11⁄2d. the gallon | 9 | 12 | 0 |
| Gas, 857,667 cubic feet of, at 15s. the thousand cubic feet | 643 | 5 | 0 |
| Total for products, | £. 828 | 19 | 0 |
From the result of this process it appears, that at the expence of 265l. 17s. 61⁄2; the value of the products obtained is £ 828. 19s.
By comparing the two preceding processes, A and B, it will be observed that the same quantity of gas was generated each day, notwithstanding there were fewer retorts in use, and less coal decomposed by process B, than by Report A, and that the expence of fuel, when the distillatory process was continued for a term of eight hours, was considerably less. Also, that the proportion of gas obtained from a chaldron of coals, was greater than when the process was continued for only six hours.
Hence, if from the products of
| process A, | £. 846 | 10 | 6 |
| we take the products of process B, | £. 828 | 19 | 0 |
| The difference is, | £. 17 | 11 | 6 |
which, being subtracted from the difference between the expenditure, as specified in the process alluded to, namely
| Process A, | £. 360 | 17 | 0 | |
| Process B, | 265 | 17 | 6 | 1⁄2 |
| The difference is | £. 94 | 19 | 5 | 1⁄2 |
| Less | 17 | 11 | 6 | |
| And leaves a balance of | £. 77 | 17 | 11 | 1⁄2 |
in favour of working eight hours charges, for one week, and producing a like quantity of gas, as had been obtained by working six hours charges.
Thus, having compared the quantity of coals actually used when working six hours charges, with what was used to produce a like quantity of gas from eight hours charges, I shall next point out, in process C, the quantity of gas obtained when working the same number of retorts for a period of eight hours which had been worked at the process of six hours.