A Trip to Venus by John Munro
page 21 of 191 (10%)
page 21 of 191 (10%)
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that is, after it had crossed the intervening space. The charge of
gun-cotton was calculated to give the projectile a velocity sufficient to carry it past the 'dead-point,' where the gravity of the earth upon it was just balanced by that of the moon, and enable it to fall towards the moon for the rest of the way. The sudden shock of the discharge on the car and its occupants was broken by means of spring buffers and water pressure." _G_. "The last arrangement was altogether inadequate." _I_. "It was certainly a defect in the scheme." _G_. "Besides, the initial velocity of the bullet to carry it beyond the 'dead-point,' was, I think, 12,000 yards a second, or something like seven miles a second." _I_. "His estimate was too high. An initial velocity of 9,000 yards, or five miles a second, would carry a projectile beyond the sensible attraction of the earth towards the moon, the planets, or anywhere; in short, to an infinite distance. Indeed, a slightly lower velocity would suffice in the case of the moon, owing to her attraction." _G_. "But how are we to give the bullet that velocity? I believe the highest velocity obtained from a single discharge of cordite, one of our best explosives, was rather less than 4,000 feet, or only about three-quarters of a mile per second. With such a velocity, the projectile would simply rise to a great height and then fall back to the ground." _I_. "Both of these drawbacks can be overcome. We are not limited to a |
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