458 Mr. W. Herapath's Experiments on Oil and Coal Gas. 



mitteeof the House of Commons. The oil gas used had a spe- 

 cific gravity '96, and the coal gas '^3 : the former nearly 6pei- 

 cent, heavier than the mean of nine samples I have tried, and 

 the latter as light as the worst coal gas I ever met with : the 

 mean of the nine of oil was '900 and of eight of coal '500, the 

 first nearly as much below olefiant gas •974' as the latter is be- 

 low light carburetted hydrogen -555 ; and the relative lights 

 of such gases would be, calculating from our experiments, 

 about 2^ to 1, or from those gentlemen's about 2| to 1. I 

 should wish also to show that the oil gas mentioned above was 

 better than what was commonly made from the same appa- 

 ratus ; for the gentlemen who owned it stated that they pro- 

 duced upon an average 112^ cubic feet per gallon of oil ; now 

 112|- cubic feet at '96 weigh 137 oz., while the gallon of 

 oil from which it was made would have weighed but 123 oz., 

 out of which must be taken some ounces for water which oxy- 

 gen contained in the oil would form; and some unknown 

 •quantit}', always amounting to several per ce7its., in our experi- 

 ments 1 2, for carbon left in the i-etort. These circumstances 

 show that there must be a mistake somewhere, — either that the 

 quantity of gas made is overstated, or that the quality must 

 have been very inferior. 



We have tried some experiments as to the cheapness of 

 the two gases compared with sperm oil. In set 1st, Ex- 

 periment 5, 158 grs. of oil burnt in an Argand lamp, having 

 a wick x%ths and hole y^jths of an inch in diameter, were equal 

 to 1 cubic foot of coal gas sp. gr. -5433, and to '42 cubic loot 

 of oil gas sp. gr. -876; or 1 gallon of oil price 6s. is equal to 



340 cubic feet coal gas 5s. Id. 



143 oil gas 7s. l^d. 



Again, a coal gas sp. gr. '448 (last of the charge) was in the 

 same lamp equalled by 133^ grs. oil, and coal gas sp. gr. -603 

 by 184 grs. ; or from the three sets 361 cubic feet of coal gas, 

 5s. 4f r/., would be equal to 1 gallon sperm oil. With a large 

 Argand lamp, hole 1| inch, wick If inch diameter, 190 grs. oil 

 were equal to 1 foot coal gas, or 1 gallon to 283 cubic feet 

 price 45. 2|rf. : with the small lamp before mentioned, oil gas 

 sp. gr.^ 1-009 required 523 grs. to equal 1 cubic foot, or 1 gal- 

 lon of oil = to 103 cubic feet, price 5s. l^d. From these 

 and more experiments, taking the means, I have found the re- 

 lative prices would stand thus: 



One gallon sperm oil, price 6s. would be equal to 



361 cubic feet coal gas sp. gr. -500, price 5s. 4ffl', 



or 144 oil gas sp. gr. -900, price 7i-. 2|</. 



Or, calculating in the same way from the experiments brouglit 

 before the House of Commons by the two gentlemen before 



meutiuued, 



