CONSTRUCTION OF RETORTS. 81 



is taken up by the coke, forming carbonic acid, which is again taken up by the lime in 

 the purifying process 5 the nitrogen, with the carbon of the tar, forming cyanogen, whilst 

 the hydrogen unites with another portion of carbon and forms carburetted hydrogen. 



" It will thus be seen that about 50 per cent, of the products of the distillation, which 

 are condensed in the hydraulic main and carried off with the gas to the condenser in the 

 ordinary retorts, are by my patent retorts productive of 35 per cent, more gas, and 

 having it entirely in your power in the course of two hours to change the quantity and 

 quality of the gas with the least possible trouble, which is an advantage that cannot be 

 accomplished by the ordinary process in less than five times that period. 



" This I believe to be quite correct, and without dissimulation, or advancing any opi- 

 nions but what my experience leads me to think are true, 



" To Samuel Clegg, Jun., Esq., " I remain, &c. 



London." " JoHN BRUNTON." 



PLATE V. 



RECIPROCATING RETORT. 



The arrangement represented in this Plate is the invention of Mr. George 

 Lowe. 



It has been stated by Mr. Brunton, that the first portion of vapour produced 

 by coal when undergoing destructive distillation in ordinary retorts will, when 

 converted into gas, form that of the most brilliant quality, and it is to effect 

 this that the following arrangements have been patented. As the opinion of 

 Mr. Lowe on such matters stands amongst the highest in the kingdom, it may 

 be taken in this case without hesitation. 



Fig. 1. is a front elevation of two pairs of retorts. A 1 , A 2 , A 3 , A 4 are the 

 retorts ; BB . . the stand-pipes; C 1 , C 2 , C 3 , C 4 slide-valves for opening and 

 shutting off the communication between the retorts and hydraulic main ; D is 

 the hydraulic main. 



Fig. 2. is a back elevation of the same bench of retorts ; E E are pipes, by 

 which the interiors of the retorts are connected; F l F 2 are slides for closing 

 that connection when required. 



Fig. 3. is a plan of the lower pair of retorts ; the operation is as follows : 

 Supposing the entire bench to be at the requisite heat for decomposing the 

 coal, and that they are working six-hours' charges, the lids of the retorts A 1 

 and A 3 are removed, and by means of scoops (each half the length of the 

 retort) the coal is introduced at both ends, and the lids immediately secured 



M 



