already-mentioned delay of the moon, or, in round numbers, 64°. Thus, at
the moment of firing, the visual radius applied to the moon will
describe with the vertical line of the place an angle of 64°.

"Such are the answers to the questions proposed to the Observatory of
Cambridge by the members of the Gun Club.

"To sum up--

"1st. The cannon must be placed in a country situated between 0° and 28°
of north or south latitude.

"2nd. It must be aimed at the zenith of the place.

"3rd. The projectile must have an initial speed of 12,000 yards a
second.

"4th. It must be hurled on December 1st of next year, at 10hrs. 46mins.
40secs. p.m.

"5th. It will meet the moon four days after its departure on December
4th, at midnight precisely, at the moment she arrives at her zenith.

"The members of the Gun Club ought, therefore, at once to commence the
labour necessitated by such an enterprise, and be ready to put them into
execution at the moment fixed upon, for they will not find the moon in
the same conditions of perigee and zenith till eighteen years and eleven
days later.

"The staff of the Observatory of Cambridge puts itself entirely at their