or diminished, in any particular place, will give a Reason for the greater and lesser height of the Mercury in the Baroscope: But to direct us in the choice of the several Causes, which may be assign'd for the Increase and Decrease of the Air, 'twill not be unnecessary to enumerate some of the principal Observations made upon the Barometer, most whereof are sufficiently known already to all those that are curious in these Matters.
The First is, That in calm Weather, when the Air is inclin'd to Rain, the Mercury is commonly low.
- That in serene good settled Weather, the Mercury is generally high.
- That upon very great Winds, though they be not accompanied with Rain, the Mercury sinks lowest of all, with relation to the Point of the Compass the Wind blows upon.
- That cæteris paribus the greatest heights of the Mercury are found upon Easterly and North-Easterly Winds.
- That in calm frosty Weather the Mercury generally stands high.
- That after very great Storms