CONSTRUCTION OF RETORTS. 



61 



Fig. 10. 



The charge for the retort is placed in this ; one man takes the cross-handle, 

 and two others at the opposite end lift it with its contents up to the retort ; 

 it is then pushed forward, quite to the bottom, turned round, and withdrawn 

 immediately, and the coal left in the retort raked into an even stratum. 



The lid, previously luted, is now quickly jointed on to the retort-mouth. 

 It must be obvious that the loss of gas by this simple method is very trifling ; 

 indeed I much question whether any is lost, the whole operation not occupying 

 more than forty seconds ; whereas, when the shovel is used, the coal is thrown 

 in so much by degrees, that more gas is lost, owing to the greater length of 

 the operation, and the heat producing some effect on each separate shovel- 

 full : -in either case the loss is inconsiderable, but I am an advocate for saving 

 in every possible way. 



Previous to drawing the charge, loosen the lids of the retorts, and apply a 

 light to the issuing gas, beginning at the upper retorts. This precaution is 

 necessary to prevent explosion, or what the stokers call a " rap." 



S is the mouth-piece, ten inches long, with a socket cast on the top to re- 

 ceive the stand-pipe. There ought to be a neck to this socket, as shown in 

 the Plates ; because the joint, when close upon the top, from its greater thick- 

 ness, retains much heat, and decomposes the tar which will accumulate at this 

 place, and eventually choke the pipe with hard carbon. The length of the 

 neck may be from four to five inches. I have mentioned this, from having fre- 

 quently observed the stand-pipe jointed immediately upon the mouth-piece. 



The mouth-piece is three quarters of an inch in thickness, secured to the 

 retort by bolts, and a cement-joint made between their flanches. Iron cement 



