| Sea Scale. | Wind. | Land Scale. | ||||||||||
| 0 | to | 3 | = | Light | = | 0 | to | 1 | ||||
| 3 | " | 5 | = | Moderate | = | 1 | " | 2 | ||||
| 5 | " | 7 | = | Fresh | = | 2 | " | 3 | ||||
| 7 | " | 8 | = | Strong | = | 3 | " | 4 | ||||
| 8 | " | 10 | = | Heavy | = | 4 | " | 5 | ||||
| 10 | " | 12 | = | Violent | = | 5 | " | 6 | ||||
| Pressure in Pounds (Avoirdupois) | (Land Scale). | Velocity in Miles (Hourly). | ||||||||||
| ½ | = | 1 | = | 10 | ||||||||
| 5 | = | 2 | = | 32 | ||||||||
| 10 | = | 3 | = | 45 | ||||||||
| 21 | = | 4 | = | 65 | ||||||||
| 26 | = | 5 | = | 72 | ||||||||
| 32 | = | 6 | = | 80 | ||||||||
5. Letters to Denote the State of the Weather.
| b | denotes | blue sky, whether with clear or hazy atmosphere. |
| c | " | cloudy, that is detached opening clouds. |
| d | " | drizzling rain. |
| f | " | fog. |
| h | " | hail. |
| l | " | lightning. |
| m | " | misty, or hazy so as to interrupt the view. |
| o | " | overcast, gloomy, dull. |
| p | " | passing showers. |
| q | " | squally. |
| r | " | rain. |
| s | " | snow. |
| t | " | thunder. |
| u | " | ugly, threatening appearance of sky. |
| v | " | unusual visibility of distant objects. |
| w | " | wet, that is dew. |
A letter repeated denotes much, as r r, heavy rain; f f, dense fog; and a figure attached denotes duration in hours, as 14 r, 14 hours rain.
By the combination of these letters, all the ordinary phenomena of the weather may be recorded with certainty and brevity.
Examples.—b c, blue sky with less proportion of cloud. 2 r r l l t, heavy rain for two hours, with much lightning, and some thunder.
The above methods of recording the force of wind and state of weather were originally proposed by Admiral Sir Francis Beaufort. They are now in general use at sea, and by many observers on land.
6. Table of Expansion by Heat from 32° to 212° F.
| Platinum | 0·0008842 | of the length. | |
| Glass, Flint | 0·0008117 | " | |
| "with Lead | 0·0008622 | " | |
| Brass | 0·0018708 | " | |
| Mercury | 0·0180180 | " | |
| Water | 0·0433200, | from 39° to 212° | |
| Alcohol | 0·1100 | "32° to 174° | |
| Nitric Acid | 0·1100 | ||
| Sulphuric Acid | 0·0600 |