“Regarding question No. 3, ’What would be the duration of the projectile’s transit to which a sufficient initial speed has been given, and consequently at what moment should it be hurled so as to reach the moon at a particular point?’

“If the projectile kept indefinitely the initial speed of 12,000 yards a second, it would only take about nine hours to reach its destination; but as that initial velocity will go on decreasing, it will happen, everything calculated upon, that the projectile will take 300,000 seconds, or 83 hours and 20 minutes, to reach the point where the terrestrial and lunar gravitations are equal, and from that point it will fall upon the moon in 50,000 seconds, or 13 hours, 53 minutes, and 20 seconds.  It must, therefore, be hurled 97 hours, 13 minutes, and 20 seconds before the arrival of the moon at the point aimed at.

“Regarding question No. 4, ’At what moment would the moon present the most favourable position for being reached by the projectile?’

“According to what has been said above the epoch of the moon’s perigee must first be chosen, and at the moment when she will be crossing her zenith, which will still further diminish the entire distance by a length equal to the terrestrial radius—­i.e., 3,919 miles; consequently, the passage to be accomplished will be 214,976 miles.  But the moon is not always at her zenith when she reaches her perigee, which is once a month.  She is only under the two conditions simultaneously at long intervals of time.  This coincidence of perigee and zenith must be waited for.  It happens fortunately that on December 4th of next year the moon 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 deg. and 28 deg. 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?’