and in Table II. are exhibited the details of its composition, and the
weight and volume of air required for its combustion. The total heat
of combustion in 1 lb of water evaporated:

= 15.06 × (0.8497 + 4.265 × (0.426 - 0.035/8))
= 15.24 lb. of water from and at 212°
= 14,727 units of heat.

TABLE II.--PROPERTIES OF LLANGENNECH COAL.

---------------------+----------+------------+---------------------+
| | | |
| | | Products of |
| | Oxygen | Combustion at 32° F.|
| Analyses | required +--------+------------+
| of 1 lb. | for | | |
| of Coal. | Combustion.| Cubic | Volume |
| | Pounds. | feet. | per cent. |
---------------------+----------+------------+--------+------------+
Carbon........... | 0.8497 | 2.266 | 25.3 | 11.1 |
Hydrogen......... | 0.0426 | 0.309 | 7.6 | 3.4 |
Oxygen........... | 0.0350 | --- | --- | --- |
Sulphur.......... | 0.0042 | --- | --- | _ --- |
Nitrogen......... | 0.1045 | --- | 0.18 | | |
Ash.............. | 0.0540 | --- | --- | | |
+----------+------------+ | | 85.5 |
| | | | | |
Total........... | 1.0000 | 2.572 | --- | | |
9-1/3.lb nitrogen | --- | --- | 118.9 | | |
6 lb. excess of air. | --- | --- | 71.4 | _| |