APPENDIX.
Velocity Table.
The following is a tabular form showing the velocities of moving bodies as given by Peschel:
| Feet per second. | ||
| Rivers | 3–4 | |
| Very rapid stream | 13 | |
| Wind (ordinary) | 10 | |
| Storm | 54 | |
| Hurricane | 80–120 | |
| Sound (through air) | 1100 | |
| Sound (through metal) | 12,000 | |
| Air in vacuum | 1280 | |
| Ball from air-gun Air condensed 100 times |  | 697 |
| Musket ball | 1280 | |
| Rifle ball (at most) | 1600 | |
| Cannon ball (24-pounder) | 2450 | |
| Earth’s rotation (at equator) | 1525 | |
| Earth’s centre in its orbit | 101,061 | |
| Miles per hour. | ||
| Racehorse | 60 | |
| Pigeon | 20–30 | |
| Peregrine falcon | 120 | |
| Ocean steamers | 21 | |
| River steamers | 22 | |
| Railway train | 80 | |
| Sailing vessel | 10 | |
| Malay proa | 20 | |
| Miles per second. | ||
| Light | 200,000 | |
| Electricity | 576,000 | |
Weight of a Superficial Foot of Plate or Sheet Iron.
|
No. of the wire guage. |
Thickness in inches. |
Weight in pounds. |
No. of the wire guage. |
Thickness in inches. |
Weight in pounds. |
No. of the wire guage. |
Thickness in inches. |
Weight in pounds. |
| 1 | 40 | 5 | 8·74 | 18 | 1·86 | |||
| ⅞ | 35 | 6 | 8·12 | 19 | 1·70 | |||
| ¾ | 30 | 7 | 3⁄16 | 7·5 | 20 | 1·54 | ||
| 11⁄16 | 27·5 | 8 | 6·86 | 21 | 1·40 | |||
| ⅝ | 25 | 9 | 6·24 | 22 | 1⁄32 | 1·25 | ||
| 9⁄16 | 22·5 | 10 | 5·62 | 23 | 1·12 | |||
| ½ | 20 | 11 | ⅛ | 5 | 24 | 1 | ||
| 7⁄16 | 17·5 | 12 | 4·38 | 25 | 0·9 | |||
| ⅜ | 15 | 13 | 3·75 | 26 | 0·8 | |||
| 1 | 5⁄16 | 12·5 | 14 | 3·12 | 27 | 0·72 | ||
| 2 | 12 | 15 | 2·82 | 28 | 1⁄64 | 0·64 | ||
| 3 | 11 | 16 | 1⁄16 | 2·50 | 29 | 0·65 | ||
| 4 | ¼ | 10 | 17 | 2·18 | 30 | 0·50 |