Weatherlawyer wrote:
Meteorological Imaginations And Conjectures. Snipped

Since Mr Franklin was probably writing from Europe, perhaps cross
posting it to a real newsgroup might provide some insight.

I shall leave it stew a while for fear anyone with at least half a
brain might like to look at it before I go to town.


First off, then:
The first part is a regist of what may have been known in those days.
The attenuation of atmosphere with height certainly was:


"There seems to be a region higher in the air over all countries,
where it is always winter, where frost exists continually, since, in
the midst of summer on the surface of the earth, ice falls often from
above in the form of hail. Hailstones, of the great weight we sometimes
find them, did not probably acquire their magnitude before they began
to descend.

The air, being eight hundred times rarer than water, is unable to
support it but in the shape of vapour -a state in which its particles
are separated, as soon as they are condensed by the cold of the upper
region, so as to form a drop, that drop begins to fall.

If it freezes into a grain of ice, that ice descends.

In descending, both the drop of water, and the grain of ice, are
augmented by particles of the vapour they pass through in falling and
which they condense by their coldness, and attach to themselves."


Obvious surmising since in the days before flight the behaviour of the
atmosphere was quite unknown. So the application of logic, though
brilliant remained unproven for centuries. He knew nothing of jet
streams, supercooled water and the rest of it, though he may have had
knowledge of the adiabatic lapse rate.

I tried looking up the history of that part of meteorology, remember
that the birth of the science was not even in its infancy in those days
of the blockade.
http://en.wikipedia.org/wiki/Royal_Navy#1692-1815

(It was the British ships stationed off the trade routes, blockading
Europe that gave those supreme meteorologists FitzRoy and Beaufort the
data they would need to set up the Board of Trade Enquiry into
meteorology: )

No doubt the details of such things as might help one merchant beat
another at trade would tend to be kept a secret.

"We don't know who first devised a scale of wind force. But it would
be surprising if medieval Arab seafarers didn't use one because they
had, by the late 15th century, classified in detail virtually every
aspect of the weather that had any navigational significance.

It would be surprising, too, if the mariners of ancient times didn't
use such a scale - but as they left so few records, we can only
speculate.

The scale we all know - the one that bears Beaufort's name - was
formulated at the start of the 19th century. But accounts from 1704
show that a similar scale was in use a century earlier."
http://www.met-office.gov.uk/educati.../beaufort.html


Here is a potted history of the science of the pneumodynamics of
meteorology:

"Not long after the electric telegraph made synoptic observations
possible in near 'real time', it was realised that in regions of
'disturbed' weather, two different 'streams' of air could often be
found converging into the disturbed zone - each having markedly
different properties.

In the British Isles, Robert FitzRoy, the first director of the
Meteorological Office is usually credited with highlighting this fact
in 1863, though other workers, particularly in France, Germany, Holland
and the United States were thinking along the same lines at the same
time.

Upon the death of FitzRoy, the concept tended to falter, until later
workers took up the theme and elaborated upon it: Abercromby in 1887,
Napier Shaw and Lempfert in 1911 and of course by the 'Bergen school':
V and J Bjerknes and H. Solberg and others during and just after the
Great War."
http://www.booty.org.uk/booty.weathe.../uswfaq.htm#2B


"It is possible that, in summer, much of what is rain, when it
arrives at the surface of the earth, might have been snow, when it
began its decent; but being thawed, in passing through the warm air
near the surface, it is changed from snow to rain.

How immensely cold must be the original particle of hail, which forms
the centre of the future hailstone, since it is capable of
communicating sufficient cold, if I may so speak, to freeze all the
mass of vapour condensed round it, and form a lump of perhaps six or
eight ounces in weight."


What an immensely clever man Franklin was. But naturally he begins to
go wrong here where logic is his only method of analysis:


"When, in summertime, the run is high, and continues long every day
above the horizon, its rays strike the earth more directly and with
longer continuance, than in the winter.

Hence the surface is more heated, and to a greater depth, by the heat
of those rays."


But in his defence that is still the error made by the thought police.
That the sum of all the heat on the earth is from insolation and the
residue from the planet's creation. As if 20 or even 2000 miles of
surface could keep the depths as hot as hell for all that time.