relaiing to Gas Illumination." 41 



the tar converted into gas) 200 cubic feet of excellent coal gas, 

 and perfectly equivalent, if purified by dry lime, on the principle 

 of the Exeter patent*, to 100 cubic feet of oil gas. By this me- 

 thod, v.'hich is very cleanly and simple in its application, " all the 

 costly and offensive operation of purifying is turned into profit f 1" 

 But we have yet another product from this half-hundred weight 

 of coal, (which, thougli " costly," we consider not offensive,) that 

 of one bushel of excellent coke, which we can readily sell for four- 

 pence, i. e. for a penny more than the original cost of the coal ! 

 This source of profit is not peculiar to ourselves ; several large 

 gas concerns are now obtaining it. The thing is now put in a 

 tangible shape ; and from the data given, any one may form a 

 ratio of the comparative values of coal gas and oil gas, let their 

 prime cost differ in whatever degree. 



As to the next sentence, it contains an assertion so unqualified, 

 and yet so circumstantially told, that a person unacquainted with 

 the subject would immediately be led to believe it. But that we 

 may not lose one word of this precious sentence, we will refer to 

 the author's own words. They are these : " The oil gas has a 

 material advantage over coal gas from its peculiar richness in ole- 

 fiant gas, which renders so small a volume necessary, that one 

 cubic foot of oil gas will be found to go as for as four of coal 

 gas. This circumstance is of great importance, as it reduces in 

 the same proportion the size of the gasometers which are neces- 

 sary to contain it ; this is not only a great saving of expense in 

 the construction; but is a material convenience where room is 

 lim.ited." 



* This method of purlfy'uig is very superior to any method I have j-et 

 seen. More lime is certainly required. But after it has served this pur- 

 pose it is in a useable state to lay upon land ; and being saturated with the 

 very principles of manure, (ammonia, suipliurettcd hydrogen and carbon,) 

 it is evidently worth more to the agriculturist, tlian when in its simple 

 state of quick-lime. 



•f- It seems as if the legislature were determined to make all public gas 

 establishments adopt this method of purifying. The clause now generally 

 introduced into the Act of Parliament, preventing the carrying of any 

 sough or drain or washings into the brook or stream which carries off the 

 tilth and nuisances of the whole town, through which it runs, is no less 

 fatal to the method of purifying by lime mud, than it is severe upon the esta- 

 blishment, and prejudicial to the public. — Mark the inconsistency. By a 

 prior clause they (the (ias Establishment) are allowed to make as many 

 sewers, tanks, and drains as they please ; and yet are not allowed to let 

 these drains run into the general drain or brook of the place! What must be 

 the consequence ? And indeed, what is now actually the case ? That the wash- 

 ing water must tind it escape by filtration to the surrounding neighbourhood, 

 to the irreparable injury of the wells and cellars in that neighbourhood ! 

 Would it not be acting more liberally and fairly, to allow the gas manufar- 

 turers tli<^ same privileges as all other man\ifacturcrs are allowed ; and 

 merely subject them to a penalty on being convicted before two justices of 

 the peace for suflcring an unabated nuidancc ? 



One 



