"These are our answers to the questions proposed to the Observatory of Cambridge by the members of the Gun Club:—
"To sum up,—
"1st. The cannon ought to be planted in a country situated between between 0° and 28° of N. or S. lat.
"2ndly. It ought to be pointed directly towards the zenith of the place.
"3rdly. The projectile ought to be propelled with an initial velocity of 12,000 yards per second.
"4thly. It ought to be discharged at 10hrs. 46m. 40sec. of the 1st December of the ensuing year.
"5thly. It will meet the moon four days after its discharge, precisely at midnight on the 4th December, at the moment of its transit across the zenith.
"The members of the Gun Club ought, therefore, without delay, to commence the works necessary for such an experiment, and to be prepared to set to work at the moment determined upon; for, if they should suffer this 4th December to go by, they will not find the moon again under the same conditions of perigee and of zenith until eighteen years and eleven days afterwards.
"The Staff of the Cambridge Observatory place themselves entirely at their disposal in respect of all questions of theoretical astronomy; and herewith add their congratulations to those of all the rest of America.
"For the Astronomical Staff,