anner during an hour and three-quarters after sunset, taking
observations all the way. Ascending for the first flight, he left a
temperature of 58 degrees on the earth, and found it 55 degrees at
1,200 feet, then 43 degrees at 3,600 feet, and 29 1/2 degrees at
the culminating point of 6,200 feet. Then, during the descent, the
temperature increased, though not uniformly, till he was nearly brushing
the tops of the trees, where it was some 3 degrees colder than at
starting.

It was now that the balloon, showing a little waywardness, slightly
upset a portion of the experiment, for, instead of getting to the
neighbourhood of earth just at the moment of sunset, the travellers
found themselves at that epoch 600 feet above the ground, and over the
ridge of a hill, on passing which the balloon became sucked down with
a down draught, necessitating a liberal discharge of sand to prevent
contact with the ground. This circumstance, slight in itself, caused the
lowest point of the descent to be reached some minutes late, and, still
more unfortunate, occasioned the ascent which immediately followed to be
a rapid one, too rapid, doubtless, to give the registering instruments
a fair chance; but one principal record aimed at was obtained at least
with sufficient truth, namely, that at the culminating point, which
again was 6,200 feet, the temperature read 35 degrees, or about 6
degrees warmer than when the balloon was at the same altitude a little
more than an hour before. This comparatively warm temperature was
practically maintained for a considerable portion of the descent.

We may summarise the principal of Mr. Glaisher's generalisations thus,
using as nearly as possible his own words:--

"The decrease of temperature, with increase of elevation, has a diurnal
range, and depends upon the hour of the day, the changes being the
greatest at mid-day and the early part of the afternoon, and decreasing
to about sunset, when, with a clear sky, there is little or no change
of temperature for several hundred feet from the earth; whilst, with a
cloudy sky, the change decreases from the mid-day hours at a less rapid
rate to about sunset, when the decrease is nearly uniform and at the
rate of 1 degree in 2,000 feet.

"Air currents differing in direction are almost always to be met with.
The thicknesses of these were found to vary greatly. The direction of
the wind on the earth was sometimes that of the whole mass of air up to
20,000 feet nea