94 OASS LIGHTS. 



unvarying intensify, have brought it into great favour with th* 

 work-people. And its being fret- from the inconvenience and 

 danger resulting from the sharks and frequent snuffing of candles, 

 is a circumstance of maleri.il importance, as tending to diminish 

 the hazard of fire, to which cotton mills are known to be much 

 eposd. 



The above particulars, it is conceived, contain such information 

 as may teiul to illustrate the general advantages attending the use 

 of the gass li^ht ; but nevertheless the Royul Society may perhaps 

 not deem it uninteresting to be apprized of the circumstances 

 which originally gave rise in my mind to its application, as an 

 economical substitute for oils and tallow . 



It is now nearly sixteen years since, in a cour-e of experiments 

 I was making at Kedruth, in Cornwall, upon the quantities and 

 qualities of the gasses produced by distillation, from different 

 mineral and vegetable substances, I was induced, by some obser. 

 vations I had previously made upon the burning of coal, to try 

 the combustible property of the gasses produced from it, as well 

 as from peat, wood, and other inflammable substances. And 

 being struck with tlie great quintities of gass which they afforded, 

 as well as with the brilliancy of the light, and the facility of its 

 production, I instituted several expeiiments, with a view of ascer- 

 taining the cost at which it might be obtained, compared with that 

 of equal quantities of light yielded by oils and tallow. 



My apparatus consisted of an iron retort, with tinned copper 

 and iron tubes, through which the gass was conducted to a consider, 

 able distance ; and there, as well as at intermediate points, was 

 burned through apertures <of varied forms and dimensions. The 

 experiments were made upon coal of different qualifies, which I 

 procured from distant parts of the kingdom, for the purpose of 

 ascertaining which would give the most economical results. The 

 gass was also washed with water, and other means were employed 

 to purify it. 



In the year 1798 I removed from Cornwall to Messrs. Boulton, 

 Watt, and Go's, works for the manufactory of steam engines, at 

 the Soho foundry, and there I constructed an apparatus, upon a 

 larger scale, which, during many successive nights, was applied to 

 the lighting of their principal building; and various new methods 

 were practised, of washing and purifying the gass. 



These experiments were continued, with some interruptions, 





