300 On Oil and Coal Gas. [April, 



so near the western horizon in the evenings ; and from its very- 

 slow geocentric motion, it will not afford a sufficient space to 

 attempt to deduce the form of its orbit, which is the chief object 

 to science. 



It is hoped that correct observations on the frequent appear- 

 ances and motions of those celestial visitors will, in the course 

 of time, throw new light on the theory of comets, and divest it 

 of much of the uncertainty that seems to exist in regard to the 

 form of their eccentric orbits and periodic returns. 



I am, Sir, your obedient servant, 



William Burney. 



Article XIII. 



0« Oil and Coal Gas. 

 (To the Editor of the Annals of Philosophy.) 



DEAR SIR, 



On perusing Mr. Ricardo^s paper in your last number '* Oa 



the Comparative Advantages of illuminating by Gas produced 



from Oil and from Coal," 1 felt a httle surprised that he had not 



obtained more correct information respecting the value of coal 



fas ; for he states that the selling price of coal gas is not less, 

 ut " in some of the provincial towns and cities more than 155. 

 per 1000 feet." In speaking of the profits of Gas Companies, 

 he says, ^' The highest return quoted, which is of the Bristol 

 Gas Company, is 10 per cent, and the chartered Company in 

 London, which possesses advantages superior to ani/, only divides 

 eight per cent." Not knowing the price of gas at the chartered 

 Company, I assume that it is 155. per 1000 feet to the consumer. 

 The Sheffield Gas Light Company retail their gas at 125. per 

 1000 feet, and allow a diiicount of from 5 to 20 per cent, in pro- 

 portion to the rental. All consumers of gas whose rental is 20/. 

 per annum, or upwards, are allowed a discount of 20 per cent. 

 When the discount is allowed, I believe the average to tne whole 

 town is at about IO5. 6d. ptr 1000 feet, and yet the Sheffield 

 Gas Light Company has divided a projit of 10 per cent, the first 

 year. This certainly proves that the Sheffield Gas Light Com- 

 mittee are either better managers of the trust confided in them, 

 or that the chartered Company does not possess advantages 

 superior to any other Gas Company. But what will Mr. R. say- 

 to the Derby Gas Company when I inform him that they charge 

 only 75. 6d. per 1000 feet to the consumer ; but as their con- 

 cern is only m its infancy, I cannot state their profits. If we 

 allow that one foot of oil gas is equal in illuminating power to 



