THE GAS COALS OF OHIO. 723 
of coal that yields 5 feet to the pound. The use of the richer coal 
reduces the cost of necessary plant, labor in retort house, wear and tear 
of retorts, and the consumption of coke for fuel. The illuminating 
power being the same, and the value of the richer coal being placed at 
$2.50 per net ton at gas-works, then the value of the leaner coal will not 
exceed $1.95, and probably not $1.90, especially to small works, not 
using or disposing of their ammoniacal liquor. But, as a rule, the 
richer coal gives gas of a higher illuminating power than does the leaner 
article. Coal giving a high candle power gas often possesses great 
value, even when giving an inferior coke, and not extraordinary yield in 
quantity, in this, that it may enable the gas-works to use a poor coal, or 
a coal that makes a low candle-power gas, but which from its nearness 
or convenience to the works, can be obtained, relatively, much cheaper 
than good gas coal. 
General figures and calculations cannot be given that will be of 
much value or interest to works in any particular locality, but with 
the number of gas-works located in the coal producing territory of the 
State, it seems that by a proper admixture of the local coals that can 
be obtained cheaply with the cannel of numbers 3, 3a and 36 (the 
Mercer and Tionesta coals), a much greater quantity of Ohio coals 
might be used with profit to the gas companies. 
In many localities local coals, say of numbers 5 or 6 (the Kittanning 
seams), may be obtained at $1.50 per ton, and cannel at $3.00 per ton. 
Number 5 will produce 9,000 feet to the net ton of 13 candle gas. No.3 
cannel, 9,000 feet, of 24 candle gas, the mixture giving a coal at $2.25 
per ton that yields 9,000 feet of 18.5 candle gas, with good coke from half 
the coal, and inferior coke from the other half or from the cannel coal. 
Weight and character of coke ranks third in determining the value of 
gas coals. In both quantity of coke produced from a ton of coal, and in the 
quality of such coke, Ohio coals are generally inferior to Youghiogheny 
coal. The Pittsburgh seam in Ohio gives a coke inferior only perhaps 
in quantity of sulphur it contains, and possibly a slight excess of ash. 
The number 5 seam, of southern Ohio, gives a coke very similar in 
appearance to Youghiogheny, but carries so much sulphur as to be use- 
less for many purposes for which good coke is used. Number 6 seam 
gives a lighter and more pulverulent coke, containing more sulphur 
than the Youghiogheny gas coke. Its structure is such as to cause it to 
be consumed with greater rapidity, producing intense heat and fluxing 
