Dr Fyfe on the Comparative Value of Oil and Coal Gas. 185 
So that 8000 feet might be made at L. 8, 8s., but we must 
make allowance for loss before this is sent to the consumers, 
which is equal to about one-sixth *, reducing the quantity to 
6600 feet, making the cost price 25s. 6d. Let us inquire, then, 
if made at this rate, and taking it for granted that the illumina- 
ting power is as three to one, consequently sold for thrice the 
price of coal-gas, it would afford a profit to share-holders. 
Though the Leith Company has now only six Retorts, yet, in 
extending their works, they will require six more, and the capi- 
tal is L. 15,000, 
Twelve Retorts should make 16,000 feet per day ; but if this 
be the greatest quantity that can be made, and necessary for win- 
ter consumption, the demand must be less in summer. Taking 
the number of hours the gas would be required during the year, 
the consumption would amount to very nearly 4,000,000 feet. 
The expence of making this, taking into calculation the loss by 
leakage, he. amounts to - L. 5100 
And sold at 36s. per 1000 feet, would yield - 7200 
Leaving a surplus of - - - - L. 2100 
to pay the interest on L. 15,000, and lay by a sinking fund for 
contingencies. 
But this is proceeding on the supposition, that, from its sup- 
posed illuminating power or good qualities, it would be pur- 
chased by many at three times the price, (I mean foot for foot), 
the oil-gas necessary for yielding a certain light, being only one- 
third of the quantity of that of coal-gas. If this is not done, 
then oil-gas cannot, at the price at which it is now ?:iade, com- 
pete with coal-gas. 
It may be asked, if oil-gas can be manufactured at about 
25s. 6d. per 1600 feet, why does a company, such as that at Leith, 
charge 40s., (and this is the lowest which has yet been char- 
ged) ? To this the answer is obvious. They are not now 
making it at 25s. 6d. Every establishment of this nature is, 
at its commencement, not in full employment, and there is not 
therefore a sufficient income from the quantity of gas consumed 
at present, to meet the expenditure, and also to return a profit 
on the capital, supposing it sold at a lower rate. Hence from 
* This is the actual loss, as ascertained by various trials. 
