would be convenient to call the length of this pendulum a yard, and make it the standard of all our measures of length. But as there is a yard already established, it will do equally well to tell the length of the pendulum in yards. It was found by commissioners appointed for the purpose, that this pendulum in London was 39·1393 inches, or about one yard, three inches, and ⁵/₃₆ of an inch. The following is the division of the
MEASURES OF LENGTH.
The lowest measure is a barleycorn.6
| 3 | barleycorns are | 1 inch | 1 in. |
|---|---|---|---|
| 12 | inches | 1 foot | 1 ft. |
| 3 | feet | 1 yard | 1 yd. |
| 5½ | yards | 1 pole | 1 po. |
| 40 | poles or 220 yards | 1 furlong | 1 fur. |
| 8 | furlongs or 1760 yards | 1 mile | 1 mi. |
| Also | |||
| 6 | feet | 1 fathom | 1 fth. |
| 69⅓ | miles | 1 degree | 1 deg. or 1°. |
A geographical mile is ¹/₆₀th of a degree, and three such miles are one nautical league.
In the measurement of cloth or linen the following are also used:
| 2¼ | inches are | 1 nail | 1 nl. |
|---|---|---|---|
| 4 | nails | 1 quarter (of a yard) | 1 qr. |
| 3 | quarters | 1 Flemish ell | 1 Fl. e. |
| 5 | quarters | 1 English ell | 1 E. e. |
| 6 | quarters | 1 French ell | 1 Fr. e. |
- MEASURES OF SURFACE, OR SUPERFICIES.
All surfaces are measured by square inches, square feet, &c.; the square inch being a square whose side is an inch in length, and so on. The following measures may be deduced from the last, as will afterwards appear.
| 144 | square inches are | 1 square foot | 1 sq. ft. |
|---|---|---|---|
| 9 | square feet | 1 square yard | 1 sq. yd. |
| 30¼ | square yards | 1 square pole | 1 sq. p. |
| 40 | square poles | 1 rood | 1 rd. |
| 4 | roods | 1 acre | 1 ac. |
Thus, the acre contains 4840 square yards, which is ten times a square of 22 yards