OF WORKING CYLINDRICAL RETORTS.

93

the practice of the latter method an increase ofsaleable products amounting to

,£187 2 n

obtained at 29 3 0 less expence;

consequently there is a -

balance of . . £216 5 71 in favour of

working the retorts, as stated in process C, overthat method shewn in process A ; and in such pro-portion, let the number of retorts worked be whatit may, an advantage will always be gained inthis mode of manufacturing coal gas, by wofkingthe retorts at eight hours charges, as the workmencall it, in preference to adopting the shorterprocess.

From a series of operations made# with twentyparallelopipedal and with twenty cylindrical retorts,worked for one month, it has been ascertained thatthe decomposition of coal is most economicallyconducted when each retort is charged with 100pounds of coal, and the distillatory process becontinued for eight hours. Two men, one by dayand one by night, can attend nine or ten retorts.

* By H. Morrison, Esq. and Self; the coal used, was Newcastle(Bewick and C'raister’s Walls End) coal.