ony's feet; while straps
attached to the hoop were passed under the animal's body, preventing it
from lying down or from making any violent movement. This the creature
seemed in no way disposed to attempt, and when all had been successfully
carried out and an easy descent effected at Beckenham, the pony was
discovered eating a meal of beans with which it had been supplied.

Several interesting observations have been recorded by Green on
different occasions, some of which are highly instructive from a
practical or scientific point of view. On an ascent from Vauxhall, in
which he was accompanied by his friend Spencer and Mr. Rush, he recorded
how, as he constantly and somewhat rapidly rose, the wind changed its
direction from N.W. through N. to N.E., while he remained over the
metropolis, the balloon all the while rotating on its axis. This
continual swinging or revolving of the balloon Green considers an
accompaniment of either a rapid ascent or descent, but it may be
questioned whether it is not merely a consequence of changing currents,
or, sometimes, of an initial spin given inadvertently to the balloon at
the moment of its being liberated. The phenomenon of marked change which
he describes in the upper currents is highly interesting, and tallies
with what the writer has frequently experienced over London proper. Such
higher currents may be due to natural environment, and to conditions
necessarily prevailing over so vast and varied a city, and they may be
able to play an all-important part in the dispersal of London smoke
or fog. This point will be touched on later. In this particular voyage
Green records that as he was rising at the moment when his barometer
reached 19 inches, the thermometer he carried registered 46 degrees,
while on coming down, when the barometer again marked 19 inches, the
same thermometer recorded only 22 degrees. It will not fail to be
recognised that there is doubtless here an example of the errors alluded
to above, inseparable from readings taken in ascent and descent.

A calculation made by Green in his earlier years has a certain value. By
the time he had accomplished 200 ascents he was at pains to compute
that he had travelled across country some 6,000 miles, which had been
traversed in 240 hours. From this it would follow that the mean rate
of travel in aerial voyages will be about twenty-five miles per hour.
Towards the end of his career we find it stated by Lieutenant G. Grover,
R.E.,