Mists A General Mist Before The Sun Rises Near The Full Moon Fair Weather

THIS is a general and a very extensive Observation, which enables us to

judge of the Weather for about a Fortnight, and there is very great

Reason to believe that it will very rarely deceive us. In order to

convince the Reader of this, it will be necessary to explain, as far as

we are able, the Causes of this.

MISTS are observed to happen when the Mercury in a Barometer is either

very low of very high. Th
y happen when it is high after the Region of

the Air has continued calm a good while, and in the mean time a great

Abundance of Vapours and Exhalations have been accumulated, making the

Air dark by their quantity, and the disorderly Disposition of their

parts. They happen when the Mercury is low, sometimes because the

Rarity of the Air renders it unable to sustain the Vapours, which

therefore descend and fall through it.

BUT none of these Cases agree with the Observation at the Head of the

Page, and therefore to form a true judgment of the Weather, we must

distinguish between them and the Case which explains the Observation.