90 CONSTRUCTION OF RETORTS. 



The first is that of Mr. Grafton, the second that of Mr. Spinney, which is 

 decidedly inferior in every respect to the former, both from its greater thick- 

 ness and number of joints, and from its incomplete setting. The quantity of 

 fuel required by each for decomposing the coal will be stated hereafter. 



The first idea of adopting fire-clay as a substitute for metal in the construc- 

 tion of retorts occurred to Mr. Grafton in the year 1820, when he took out a 

 patent for the invention ; the first of them erected in this kingdom was at the 

 manufactory of Messrs. Butcher, in Wolverhampton. This retort was of the 

 square form, but it was soon afterwards altered to the oven, or D-shape, 

 which form has been adopted ever since, as shown in the engraving ; large 

 numbers having been put up under his direction in different parts of this 

 kingdom and in several towns on the Continent. 



The reader will fully understand their plan of construction from the eleva- 

 tion and sections in Plate VII., which require no description, except that I 

 may remark that the bottom is exposed directly to the heat of the fire, and is 

 slightly " cambered," or curved upwards, to enable it with more certainty to 

 retain its form. The cement with which the parts of the oven are jointed is 

 a composition which Mr. Grafton has been at much pains to render perfect, 

 but he has not favoured me with the materials of which it is formed. It seems 

 to be an excellent substance, and when the interior is coated with it, becomes 

 vitrified and quite gas-tight under considerable pressure. 



During the first seven years after their introduction great prejudice and 

 opposition from interested bodies existed against the plan ; and to such 

 an extent did this proceed, that in one of the principal gas-works of the 

 metropolis, where six of the largest ovens of this description were set up at a 

 great cost, a plot was almost simultaneously laid for their destruction, which 

 soon produced the effect desired by the contrivers. The same fate attended 

 two similar retorts erected at Montpelier, where they were wilfully destroyed. 

 It is but justice to add, that the Directors of both Companies afforded Mr. 

 Grafton every advantage and facility for a fair trial, and in the first instance 

 offered a large reward for the discovery of the persons who had designed and 

 occasioned the loss. I mention this as one example out of many, to show that 

 new inventions, however valuable, which profess to make great changes, 

 rarely meet with encouragement in the first instance. As a further proof of 

 this remark, I may notice the long time lost before the immense advantages 

 offered by the Meter to gas companies were acknowledged or appreciated. At 



