Water is practically non-elastic. A pressure has been applied of 30,000 pounds to the square inch and the contraction has been found to be less than one-twelfth.
The surface of water at rest is horizontal. A familiar example of this may be noted in the fact that the water in a battery of boilers seeks a uniform level, no matter how much the cylinders may vary in size.
A given pressure or blow impressed on any portion of a mass of water confined in a vessel is distributed equally through all parts of the mass; for example a plug forced inwards on a square inch of the surface of water, is suddenly communicated to every square inch of the vessel’s surface, however large, and to every inch of the surface of any body immersed in it.
Weight and Capacity of Different Standard Gallons of Water.
| Cubic inches in a Gallon. | Weight of a Gallon in pounds. | Gallons in a cubic foot. | Weight of a cubic foot of water, English standard, 62.221 lbs. Avoirdupois. | |
|---|---|---|---|---|
| Imperial or English | 277.264 | 10.00 | 6.232102 | |
| United States | 231. | 8.33111 | 7.480519 |
STORING AND HANDLING OF COAL.
The best method of storing coal is a matter of economy and needs the attention of the engineer.
Coal, as it comes from the mine, is in the best possible condition for burning in a furnace; its fracture is bright and clean, and it ought to be preserved up to the time of using it in such manner as to avoid as much as possible any alteration of its condition so as to prevent deterioration.