ture diminished,
with only slight deviations from a perfect regularity. At the height
of 18,636 feet the thermometer subsided to 32 deg. 9', on the verge of
congelation; but it sunk to 14 deg. 9' at the enormous altitude of 22,912
feet above Paris, or 23,040 feet above the level of the sea, the
utmost limit of the balloon's ascent."

The high range of the barometer indicated a very considerable elevation
of the trade at the time Gay-Lussac made his ascension. I am not aware
that it has since been found at so great an elevation, in so high a
latitude, though it is undoubtedly elevated by the interposition of a
large volume of N. W. air, upon some occasions, to nearly the same
altitude with us.

In the extract in relation to the ascension of Gay-Lussac, we have another
of the thousand hastily-adopted and absurd hypotheses connected with the
caloric theory. It is obviously and utterly _impossible_ that in addition
to the ordinary accumulation of heat at the surface of the earth "_as the
day advanced_"--that is, _during the forenoon_, warm currents should
ascend, unobserved by Gay-Lussac during an ascent of 12,000 feet--not
_affecting in the least_ so large an intervening body of the atmosphere or
his thermometer, and in such immense volumes as to increase the warmth of
a stratum of 4,000 feet in depth, an average of 3 deg. of Fahrenheit, and to
the extent of 6 deg. at the center.

Very few balloon ascensions have been made with a view to scientific and
accurate observation. But other aeronauts have met the counter-trade at
different altitudes, and in both clear and stormy weather.

Recently, in 1852, four ascensions were made in England, under the
direction of the Kew Observatory Committee, of the British Association. I
copy from the August number of the "London, Edinburg, and Dublin
Magazine," for 1853, the following condensed amount of the result:

"The ascents took place on August 17th, August 26th, October 21st,
and November 10th, 1852, from the Vauxhall Gardens, with Mr. C.
Green's large balloon.

"The principal results of the observations may be briefly stated as
follows:

"Each of the four series of observations shows that the progress of
the temperature is not regular at all heights, but that at a certain
height (_varying on different days_) the regular diminution becomes
arrested, and for the space of about 2,000 feet the temperature