126 Mr. Murdoch’s Account of the 
three circular apertures or perforations, of about a thirtieth of 
an inch in diameter, one at the point of the cone, and two 
lateral ones, through which the gas issues, forming three 
divergent jets of flame, somewhat like a fleur-de-lis. The 
shape and general appearance of this tube, has procured it 
among the workmen, the name of the cockspur burner. 
The number of burners employed in all the buildings, 
amounts to 271 Argands, and 63 3 cockspurs ; each of the 
former giving a light equal to that of four candles of the de- 
scription abovementioned ; and each of the latter, a light equal 
to two and a quarter of the same candles; making therefore 
the total of the gas light a little more than equal to that of 
2300 candles. When thus regulated, the whole of the above 
burners require an hourly supply of 1250 cubic feet of the 
gas produced from cannel coal ; the superior quality and quan- 
tity of the gas produced from that material having given it 
a decided preference in this situation, over every other coal, 
notwithstanding its higher price. 
The time during which the gas light is used, may, upon an 
average of the whole year, be stated at least at two hours per 
day of twenty -four hours. In some mills, where there is over 
work, it will be three hours ; and in the few where night- 
work is still continued, nearly twelve hours. But taking two 
hours per day as the common average throughout the year, 
the consumption in Messrs. Philips’ and Lee’s mill, will be 
1250 x2 = 2500 cubic feet of gas per day; to produce which, 
seven hundred weight of cannel coal is required in the retort. 
The price of the best Wigan cannel (the sort used) is 13^. 
per cwt. ( 22 s. 6 d. per ton), delivered at the mill, or say about 
eight shillings for the seven hundred weight. Multiplying by 
