"Jules Verne's "From the Earth to the Moon" and "A Trip Around It"" - читать интересную книгу автора

present herself in the most favorable position, etc.?"

Answer.-- After what has been said above, it will be
necessary, first of all, to choose the period when the moon will
be in perigee, and also the moment when she will be crossing
the zenith, which latter event will further diminish the entire
distance by a length equal to the radius of the earth, i. e.
3,919 miles; the result of which will be that the final passage
remaining to be accomplished will be 214,976 miles. But although
the moon passes her perigee every month, she does not reach the
zenith always at exactly the same moment. She does not appear
under these two conditions simultaneously, except at long
intervals of time. It will be necessary, therefore, to wait for
the moment when her passage in perigee shall coincide with that
in the zenith. Now, by a fortunate circumstance, on the 4th of
December in the ensuing year the moon will present these
two conditions. At midnight she will be in perigee, that is,
at her shortest distance from the earth, and at the same moment
she will be crossing the zenith.

On the fifth question, "At what point in the heavens ought the
cannon to be aimed?"

Answer.-- The preceding remarks being admitted, the cannon
ought to be pointed to the zenith of the place. Its fire,
therefore, will be perpendicular to the plane of the horizon;
and the projectile will soonest pass beyond the range of the
terrestrial attraction. But, in order that the moon should
reach the zenith of a given place, it is necessary that the
place should not exceed in latitude the declination of the
luminary; in other words, it must be comprised within the
degrees 0@ and 28@ of lat. N. or S. In every other spot the fire
must necessarily be oblique, which would seriously militate
against the success of the experiment.

As to the sixth question, "What place will the moon occupy in
the heavens at the moment of the projectile's departure?"

Answer.-- At the moment when the projectile shall be discharged
into space, the moon, which travels daily forward 13@ 10' 35'',
will be distant from the zenith point by four times that quantity,
i. e. by 52@ 41' 20'', a space which corresponds to the path
which she will describe during the entire journey of the projectile.
But, inasmuch as it is equally necessary to take into account the
deviation which the rotary motion of the earth will impart to the
shot, and as the shot cannot reach the moon until after a deviation
equal to 16 radii of the earth, which, calculated upon the moon's
orbit, are equal to about eleven degrees, it becomes necessary to
add these eleven degrees to those which express the retardation of
the moon just mentioned: that is to say, in round numbers, about