sot M. Juste Preuss on Oil Gas. 



gas companies united, or, so to speak, leagued together, against 

 this too dangerous competitor. 



Oil gas possesses some characteristic properties which have 

 procured it this preference which is given to it in England over 

 coal gas. These properties not being generally known, I 

 shall state some of the most remarkable. One single cubic foot 

 of oil gas gives as much light as 3^ cubic feet of coal gas *. 

 By this important fact the capacity of the gasometers (the most 

 inconvenient part of the former system of lighting) is now 

 reduced to less than a third part; the pipes to one third of 

 their former capacity ; the size of the retorts, stoves, and ap- 

 pai-atus for purifying and condensing, to one sixth ; the cost 

 of the apparatus generally, and the expense of keeping them 

 up, to one third ; lastly, the labour to less than the eighth 

 part of that which it costs in a large establishment to feed 

 with coal gas an equal number of burners of a given in- 

 tensity. It will perhaps be objected to me, that the first 

 material, the oil, on the one hand, is a dear and valuable com- 

 modity, whilst, on the other, coal is much less so in proportion. 

 I grant it as regards certain countries ; but I will add, that the 

 daily expenses of a gas establishment are of two natures, — 

 either permanent, or susceptible of variation according as the 

 sale of the gas diminishes or augments : the first are princi- 

 pally composed of the interest on the capital employed, of the 

 rent of premises, and of the labour, as the labourers cannot be 

 dismissed during the summer months, who have been in- 

 structed at an expense during the winter. Now these perma- 

 nent expenses are inconsiderable in an oil gas work, and, com- 

 paratively, very great in a coal gas establishment. The second 

 class of expenses includes the raw material, the consumption of 

 <vhich follows in exact proportion the sale of gas ; and on this 

 head gas works of each kind enjoy the same advantage. The win- 

 ter season, which brings with it long evenings and revives balls, 

 concerts, masonic meetings, &c., augments and often increases 

 tenfold the demand for light. A gas establishment ought to be 

 prepared to meet those often unexpected calls, all of which 

 decrease, and partly disappear with spring. Here then is what 

 happens to the two kinds of lighting establishments, as Dr. 

 Ricardo has judiciously observed before me : it is, that in the 

 coal gas work the great expense remains the same, and the lesser 

 expense diminishes ; whilst in the manufactory of oil gas the 

 lesser expense continues, and the great expense decreases, or 

 even ceases, in equal proportion with the sale of light. 



The inconvenient heat diffused by the combustion of coal 



* Each being of the mean quality, that is to say, specific gravity : as for 

 example the coal gas 0-4069, and the oil ga? 0'9395, the air being I'OOOO. 



gas 



