602 T/ie Architectural Review and American Builders' Journal. [April, are all four inches in diameter ; and are supplied with the necessary stops and drips, to insure the constant working of the apparatus and control the different parts. Works of this capacity will cost about six thousand five hundred dollars, say : For building and tank, . $3,000 Iron work complete, . . 3,500 $6,500 The arrangement of these works is so simple, that any man of ordinary intel- ligence, can be instructed so as to take charge of them in a few days. Estimated CostN>f Making Gas by these Works. 1st. When an average of 2,000 feet per day is made : Interest ($6,500, at 8 per cent.) for one day, . . $1 42 Coal, 470 lbs., plus 15 per cent, leakage, - 2 Vo°o tons, at $5, Labor, one man, .... Repairs, wear, etc., at 15 cts. per 1,000 feet, . 1 35 1 50 30 $2.29 per thousand feet. $4 57 2d. When an average of 3,0U0 feet per day is made : Interest ($6,500, at 8 per cent.) for one day, . . $1 42 Coal, 705 lbs., plus 12 per cent, for leakage, etc., '2 7 o 9 o°o tons . at $5, . . . 1 98 Labor, one man, . . . Repairs, etc., at 12 cents per 1,000 feet, .... $1.75 per thousand feet. 50 36 $5 26 3d. When an average of 4,000 feet per day is made : Interest ($6,500, at 8 per cent.) for one day, . . $1 42 Coal, 940 lbs., plus 10 per cent, for leakage, etc., 3ffoo tons at 2 59 1 50 44 $5 95 Less 200 lbs. coke, at ct. 50 Labor, one man, .... Repairs, wear, etc., at 11 cents per 1,000 feet, . . .36 per thousand feet. $5 45 4th. When an average of 5,000 feet per clay is made : Interest ($6,500, at 8 per cent.) for one day, . . $1 42 Coal, 1175 lbs., plus 8 per ' cent, for leakage,' etc., ilJg-tons, at $5, . . . 3 13 Labor, one man, .... 1 50 Repairs, wear, etc., at 10 cents per 1,000 feet, . 50 $6 60 Less 400 lbs. coke, at ct. I 00 $1.12 per thousand feet. $5 60