ADMIRAL FITZROY’S INSTRUCTIONS ON THE USE
OF THE BAROMETER IN NORTH LATITUDE.
The Barometer Rises:
For northerly wind (including from N. W. by the north to the eastward), for dry, or less wet weather, for less wind, or for more than one of these changes—except on a few occasions when rain (or snow) comes from the northward, with strong wind.
A Thermometer Falls:
For change of wind towards any of the above directions.
The Barometer Falls:
For southerly wind (including from S. E. by the south to the westward) for wet weather, for stronger wind, or for more than one of these changes—except on a few occasions when moderate wind with rain (or snow) comes from the northward.
A Thermometer Rises:
For change of wind towards the upper directions only. Moisture or dampness in the air (shown by a hygrometer) increases before or with rain, fog or dew.
| On Barometer Scales the following contractions may be useful in in North Latitudes. | And the following Summary may be useful generally throughout the world. | ||
Rise for | Fall for | Rise for | Fall for |
| NE by NW-N-E | SW by SE-S-W | Cold, dry or | Warm, wet or |
| Dry or less | Wet or more | less wind | more wind |
| wind—except | wind—except | —except wet | —except wet |
| wet from NE | wet from NE | from cold side. | from cold side. |