Mr Anderson on the lllummating Power of CoahGas, 
light as one measure of oil-gas, the conducting pipes of the for- 
mer would need to be enlarged, on that account, only in the 
subduplicate ratio of 1 to 2, or as 5 to 7 ; while the gas-holders 
would require to be increased in the subtriplicate ratio of 1 to 2 ; 
that is, as 4 to 5 nearly. It thus becomes evident, that the re- 
lative expence of the pipes and gas-holders for oil and coal gas, 
is but little affected by the difference between the illuminating 
powers of the gases ; and that, in point of economy, so far at 
least as regards the prime cost of the materials from which the 
gases are produced, oil and coal gas do not admit of compa- 
rison. 
But, in forming a correct and impartial estimate of the re- 
spective merits of the two gases, it is obvious that various cir- 
cumstances may require to be brought under consideration, be- 
sides the prime cost of the materials from which the gases are 
procured. A proper view of these can only be exhibited, by a 
faithful statement of the actual expence incurred by an oil and 
a coal establishment, producing an equal degree and extent of il- 
lumination. Of the former, I can only speak from the reports 
of others ; but, of the latter, I can give a distinct account, from 
what has fallen within the range of my own experience. Leav- 
ing, therefore, to persons who are more conversant with the eco- 
nomy of an oil-gas work, the task of laying before the public a 
correct statement of the expenditure and capability of that de- 
scription of a gas manufactory, I shall proceed to give a brief 
account of the original cost, as well as of the annual oujtlay and 
income of a coal-gas work, such as I have lately planned, for a 
town containing about 12,000 inhabitants. 
MASONRY, &c. 
Masonry, including a suBstantial gasometer-house, retort-house, 
purifying-house, lime-sheds, boundary-wall, pavement, brick- 
work, &c. 
Two stone-tanks for gasometers, double-walled, and clayed be- 
tween, with hewn faces, - - - - 
Carpentry and slater-work, doors, &g» 
t. S. DV 
613 10 0 
343 0 0 
323 10 0 
L. 1280 0 0 
