a moment. As the clocks in the neighbouring steeples began to
strike eleven, Ayrault touched the switch that would correspond to the
throttle of an engine, and the motors began to work at rapidly
increasing speed. Slowly the Callisto left her resting-place as a
Galatea might her pedestal, only, instead of coming down, she rose
still higher.

A large American flag hanging from the window, which, as they started,
fluttered as in a southern zephyr, soon began to flap as in a stiff
breeze as the car's speed increased. With a final wave, at which a
battery of twenty-one field-pieces made the air ring with a salute, and
the multitude raised a mighty cheer, they drew it in and closed the
window, sealing it hermetically in order to keep in the air that, had
an opening remained, would soon have become rarefied.

[Illustration: The Callisto was going straight up.]

Sylvia had waved her handkerchief with the utmost enthusiasm, in spite
of the sadness at her heart. But she now had other use for it in
trying to hide her tears. The Callisto was still going straight up,
with a speed already as great as a cannon ball's, and was almost out of
sight. The multitude then began to disperse, and Sylvia returned to
her home.

Let us now follow the Callisto. The earth and Jupiter not being
exactly in opposition, as they would be if the sun, the earth, and
Jupiter were in line, with the earth between the two, but rather as
shown in the diagram, the Callisto's journey was considerably more than
380,000,000 miles, the mean opposition distance. As they wished to
start by daylight--i. e., from the side of the earth turned towards the
sun--they could not steer immediately for Jupiter, but were obliged to
go a few hundred miles in the direction of the sun, then change their
course to something like a tangent to the earth, and get their final
right direction in swinging near the moon, since they must be
comparatively near some material object to bring apergy into play.

The maximum power being turned on, the projectile shot from the earth
with tremendous and rapidly increasing speed, by the shortest
course--i. e., a straight line--so that for the present it was not
necessary to steer. Until beyond the limits of the atmosphere they
kept the greatest apergetic repulsion focused on the upper part of
their cylinder, so that its point went first, and they encountered
least possible resistance. Looking through the floor windows,
therefore,