| Cost of Coal. | Weight of Coal. | Produce of Gas, in cubic feet. | - | [39]Equal to as many tallow candles, 12 in the pound, burning two hours; or to | Candles. | |||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mini- mum. | Maxi- mum. | Aver- age. | Min. | Max. | Aver. | Min. | Max. | Aver. | 9,516 8,651 | 11 10 | to the pound. to thdo. | |||||||||||||||||||||||||
| One Chal. of Coal, from 25 to 28 cwt. | - | 40 | s | to | 60 | s | — | 50 | s | 2,800 | to | 3,136 | — | 2,968 | 8,906 | to | 11,872 | — | 10,388 | [39] | 7,786 6,921 6,556 5,194 | 10 9 8 7 | to thdo. to thdo. to thdo. to thdo. | |||||||||||||
| One Ton | 30 | s | to | 48 | s | — | 38 | s | 6 | d | 2,240 | 6,720 | to | 8,960 | — | 7,840 | 4,325 | 5 | to thdo. | |||||||||||||||||
| One Sack | 3 | s | 4 | d | to | 5 | s | — | 4 | s | 2 | d | 233 | to | 261 | — | 247 | 741 | to | 988 | — | 814 | 3,463 | 4 | to thdo. | |||||||||||
| One Bushel | 1 | s | 2 | d | to | 1 | s | 8 | d | — | 1 | s | 5 | d | 78 | to | 87 | — | 82 | 1⁄2 | 247 | to | 330 | — | 290 | 2,595 | 3 | to thdo. | ||||||||
| One Peck | 3 | 1⁄2 | to | 5 | d | — | 4 | 1⁄4 | 19 | 1⁄2 | to | 21 | 1⁄4 | — | 20 | 1⁄4 | 61 | to | 82 | — | 71 | 1⁄2 | 1,730 | 2 | to thdo. | |||||||||||
| One Pound | 1⁄4 | 1 | 3 | to | 4 | — | 3 | 1⁄2 | 866 | 1 | to thdo. | |||||||||||||||||||||||||
| Coke.—One chaldron of coal, from 25 to 28 cwt. gives 11⁄4 to 1½ chaldron of Coke. | ||||||||||||||||||||||||||||||||||||
| Tar.—One chaldron of coal, from 25 to 28 cwt. gives from 150 to 180lb. of Tar,[39] or 15 to 18 ale gallons, 10lb. each. | ||||||||||||||||||||||||||||||||||||
| Ammoniacal Liquor.—One chaldron of coal, gives from 220 to 240lb. of Ammoniacal Liquor, or 22 to 24 ale gallons. | ||||||||||||||||||||||||||||||||||||
[39]1000lb. of Coal-Tar afford by distillation, from 260 to 265lb. of Essential Oil, or Naphtha. 1000lb. of Coal-Tar produce by mere evaporation, from 460 to 480lb. of Pitch.
Tabular View, exhibiting the illuminating power of Coal-Gas, compared with the illuminating power of Tallow Candles of different sizes.
| One chaldron of Coal produces, according to weight and quality, | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Burning. | Candles. | 12 to 1lb. | 6 to 1lb. | |||||||
| Cubic feet of Gas. | Average. | 1 | hour | = | 21,000 | = | 10,500 | |||
| From | 9,000 | to | 12,000 | 10,500 | 2 | hours | = | 10,500 | = | 5,250 |
| 6,000 | 8,000 | 7,000 | 3 | ditto | = | 7,000 | = | 3,500 | ||
| 4,500 | 6,000 | 5,250 | 4 | ditto | = | 5,250 | = | 2,625 | ||
| 3,600 | 4,800 | 4,400 | 5 | ditto | = | 4,400 | = | 2,200 | ||
| 3,000 | 4,000 | 3,500 | 6 | ditto | = | 3,500 | = | 1,750 | ||
| 2,571 | 3,428 | 3,005 | 7 | ditto | = | 3,005 | = | 1,502 | ||
| 2,250 | 3,000 | 2,625 | 8 | ditto | = | 2,625 | = | 1,312 | ||
| 2,000 | 2,666 | 2,333 | 9 | ditto | = | 2,333 | = | 1,166 | ||
| 1,800 | 2,100 | 2,100 | 10 | ditto | = | 2,100 | = | 1,050 | ||
| 1,636 | 2,191 | 1,913 | 11 | ditto | = | 1,913 | = | 956 | ||
| 1,500 | 2,000 | 1,750 | 12 | ditto | = | 1,750 | = | 875 | ||
| 1,384 | 1,846 | 1,615 | 13 | ditto | = | 1,615 | = | 807 | ||
| 1,285 | 1,714 | 1,499 | 14 | ditto | = | 1,499 | = | 749 | ||
| 1,200 | 1,600 | 1,400 | 15 | ditto | = | 1,400 | = | 700 | ||
| 1,125 | 1,500 | 1,312 | 16 | ditto | = | 1,312 | = | 656 | ||
| 1,058 | 1,111 | 1,234 | 17 | ditto | = | 1,234 | = | 617 | ||
| 1,000 | 1,333 | 1,166 | 18 | ditto | = | 1,166 | = | 583 | ||
| 947 | 1,263 | 1,105 | 19 | ditto | = | 1,105 | = | 552 | ||
| 900 | 1,200 | 1,050 | 20 | ditto | = | 1,050 | = | 525 | ||
| 857 | 1,143 | 1,000 | 21 | ditto | = | 1,000 | = | 500 | ||
| 818 | 1,095 | 956 | 22 | ditto | = | 956 | = | 478 | ||
| 783 | 1,044 | 913 | 23 | ditto | = | 913 | = | 456 | ||
| 750 | 1,000 | 875 | 21 | ditto | = | 875 | = | 437 | ||
N. B. If it be required to know, for how many hours one pound, or one peck, or one bushel, or one sack, of coal will produce Gas Light equal to that of a certain number of well-snuffed Tallow Candles, the proportion of each of the average weights of a pound, peck, bushel, or sack, to that of the average weight of a chaldron of coal, is as follows:
| 1 | lb. | = | 2968th | part of a chaldron. | |
| One peck | 20 | = | 148th | ditto. | |
| One bushel | 82 | = | 36th | ditto. | |
| One sack | 248 | = | 12th | ditto. |
Rule.—Divide with either of the above parts of weight, the number of lights opposite to their hours, and the product will be the number of lights burning for the same number of hours.
Example.—To know how many lights one peck of coal will give for six hours, divide the 148th part in 3,500, opposite to the number of six hours, the product is almost 24 lights. The same rule holds good for any given quantity or number of pounds of coal, in a chaldron, to find how many lights, or candles, 12 to the lb. or 6 to the lb. they will give for a given number of hours.