midnight
precisely
Launched on the 1st of December , at 10 hrs . 46m . 40s . P.M. , it ought to reach the moon four days after its departure , that is on the 5th of December , at midnight precisely , at the moment of her attaining her perigee , that is her nearest distance from the earth , which is exactly 86,410 leagues -LRB- French -RRB- , or 238,833 miles mean distance -LRB- English -RRB- . The principal members of the Gun Club , President Barbicane , Major Elphinstone , the secretary Joseph T. Maston , and other learned men , held several meetings , at which the shape and composition of the projectile were discussed , also the position and nature of the gun , and the quality and quantity of powder to be used . It was decided : First , that the projectile should be a shell made of aluminum with a diameter of 108 inches and a thickness of twelve inches to its walls ; and should weigh 19,250 pounds . Second , that the gun should be a Columbiad cast in iron , 900 feet long , and run perpendicularly into the earth .