51. What is the weight of a gallon of distilled water?
At the maximum density (39°.83 Fahr.), the barometer being at 30 inches, it weighs 8.33888 avoirdupois pounds, or 58373 Troy grains.
52. What are the different lengths of plummets for regulating the march of infantry?
| Common time, | 99 | steps | in a | minute, | 17.37 | inches. |
| Quick time, | 110 | “ | “ | 11.6 | “ | |
| Double quick, | 140 | “ | “ | 7.18 | “ |
53. How is a plummet made?
By means of a musket ball, suspended by a silk string, upon which the required lengths are marked; the length is measured from the point of suspension to the centre of the ball.
54. Explain how to embark and disembark artillery and its stores.
1. Divide the total quantity to be transported among the vessels, and place in each vessel every thing necessary for the service required at the moment of disembarkation, so that there will be no inconvenience should other vessels be delayed.
2. If a siege is to be undertaken, place in each vessel with each piece of artillery its implements, ammunition, and the carriages necessary to transport the whole or a part; the platforms, tools, instruments, and materials for constructing batteries; skids, rollers, scantling, and plank.
3. If a particular calibre of gun is necessary for any operation, do not place all of one kind in one vessel, to avoid being entirely deprived of them by any accident.