Winds Observe That In Eight Years' As Many Wet Years As Dry
THIS must be allowed a very extraordinary Aphorism from a Country
Shepherd, but at the same Time it is very agreeable to the Observations
of Dr. Hooke, Dr. Derham, Dr. Grew, and other able Naturalists,
who with unwearied Pains and Diligence have calculated the Quantity of
Rain falling in one Year, and compared it with what fell in another.
Lord Bacon, that Honour to our Nation and the Age which produced him,
informs us
that it was an old Opinion there was a total Revolution of
the Weather once in forty Years, and wishes it was inquired into. I
cannot tell whether this has ever been done or not, but I think there
is good Reason to conclude that there is a natural Balance established
of wet and dry Weather, as of Light and Darkness, Heat and Cold, and
other such like Variations.
IT may not be amiss to caution the Reader against a Mistake into which
the Manner of this Rule being stated may easily lead him. It is this,
that South West Winds cause Rain, and North East Winds fair Weather,
which however is not a Thing clear or certain by any means. This indeed
is true, that South West Winds and Rain, North East Winds and fair
Weather come together, generally speaking. But the Question is, which
causes the other, and a more difficult Question cannot easily be
stated, because there seems to be Facts on both sides. South West Winds
seldom continue long without Rain, this seems to prove the affirmative,
but on the other Hand, when in hard Weather, Rain begins to fall, the
Wind commonly veers to the South West, this looks as if the Rain caused
the Wind.
BUT to keep close to the Shepherd's Observation. There is one Thing
seems strongly to confirm it, which is this, that in any given Place
the Quantity of Rain one Year with another is found to be the same by
Experience, according to which the following Table has been calculated,
for the mean Quantity of Rain falling one Year with another in those
Places that are mentioned, and on this Proportion the other seems to be
founded.
At Harlem 24 Inches
Delf 27
Dort 40
Middleburg 33
Paris 20
Lyons 37
Rome 20
Padua 37-1/2
Pisa 34-1/4
Ulm 27
Berlin 19-1/2
In Lancashire 40
Essex 19-1/2