will offer these two conditions; at midnight she will be at her perigee
and her zenith--that is to say, at her shortest distance from the earth
and at her zenith at the same time.

"Regarding question No. 5, 'At what point in the heavens ought the
cannon destined to hurl the projectile be aimed?'

"The preceding observations being admitted, the cannon ought to be aimed
at the zenith of the place (the zenith is the spot situated vertically
above the head of a spectator), so that its range will be perpendicular
to the plane of the horizon, and the projectile will pass the soonest
beyond the range of terrestrial gravitation. But for the moon to reach
the zenith of a place that place must not exceed in latitude the
declination of the luminary--in other words, it must be comprised
between 0° and 28° of north or south latitude. In any other place the
range must necessarily be oblique, which would seriously affect the
success of the experiment.

"Regarding question No. 6, 'What place will the moon occupy In the
heavens at the moment of the projectile's departure?'

"At the moment when the projectile is hurled into space, the moon, which
travels forward 13° 10' 35" each day, will be four times as distant from
her zenith point--i.e., by 52° 42' 20", a space which corresponds to the
distance she will travel during the transit of the projectile. But as
the deviation which the rotatory movement of the earth will impart to
the shock must also be taken into account, and as the projectile cannot
reach the moon until after a deviation equal to sixteen radii of the
earth, which, calculated upon the moon's orbit, is equal to about 11°,
it is necessary to add these 11° to those caused by the