| 10 | tenths, | 1 inch. |
| 4 | inches, | 1 hand. |
| 12 | inches, | 1 foot. |
| 28 | inches, | 1 pace. |
| 3 | feet, | 1 yard. |
| 2 | yards, | 1 fathom. |
| 220 | yards, | 1 furlong. |
| 1760 | yards, | 1 mile. |
45. Repeat the table of avoirdupois weight.
| 47.34735 | grains, | 1 dram. |
| 16 | drams, | 1 ounce. |
| 16 | ounces, | 1 pound. |
| 28 | pounds, | 1 quarter. |
| 4 | qrs. or 112 lbs. | 1 cwt. |
| 20 | cwt. | 1 ton. |
In some of our States the ton is estimated at 2000 lbs.
46. What is the force of gravity?
It is that force of attraction exerted by the earth upon all particles of matter which tends to urge them towards its centre.
47. What is the specific gravity of a body?
The ratio of the weight of a body to that of an equal volume of some other body assumed as a standard, usually pure distilled water at a certain temperature.
48. What is the law of descent of falling bodies?
The spaces fallen through from the commencement of the descent are proportional to the squares of the times elapsed.