Distillate is the refuse left from the distillation of petroleum.
The flash point of kerosene may be between 70 and 150 degrees Fahrenheit, depending upon the grade. For illuminating purposes, do not use kerosene with the flash point lower than 120 degrees Fahrenheit.
The flash point of gasoline is 10 to 20 degrees Fahrenheit; that is, gasoline will form an imflammable vapor at temperatures as low as this.
Between 60 and 70 per cent of the common fuels are utilized in the generation of steam for heating purposes.
TABLE SHOWING GENERATION OF HEAT
| Amount | Fuel | B. T. U | ||
| 1 lb. | Anthracite coal | 13,200 | - | 13,900 |
| 1 lb. | Bituminous coal | 12,000 | - | 15,000 |
| 1 lb. | Lignite coal | 8,500 | - | 11,400 |
| 1 lb. | Wood | 8,200 | - | 9,200 |
| 1 cu. ft. | Natural gas | 900 | - | 1,000 |
| 1 cu. ft. | Illuminating gas | 500 | - | 600 |
| 1 lb. | Kerosene | 18,000 | ||
| 1 lb. | Alcohol | 12,000 | ||
| 1 lb. | Gasoline | 19,000 | ||
| 1 K.W.-hr. | Electricity | 3,400 | ||
*One pound ice in being melted will absorb 144 B. T. U.