John Munro

“ When the car came within the sensible attraction of the moon, its velocity would gradually increase as they approached each other."
G. "Always supposing the aim of the gun to have been exact. You might hit the moon, with its large disc and comparatively short range, provided no wandering meteorite diverted the bullet from its course; but it would be impossible to hit a planet, such as Venus or Mars, a mere point of light, and thirty or forty million miles away, especially as both the earth and planet are in rapid motion. ”

“ The bobbin stands for the gun-barrel, the plug for the bullet-car, and the magnetism for the ejecting force. We can arrange the wire and current so as to draw the plug or car right through the hole or barrel, and if we have a series of solenoids end to end in one straight line, we can switch the current through each in succession, and send the projectile with gathering velocity through the interior of them all. In practice the barrel would consist of a long straight tube, wide and strong enough to contain the bullet-car without flexure, and begirt with giant solenoids at intervals. ”

“ I. "Even in a vacuum, where an ordinary propeller could not act, the bullet may become a prime mover, and co-operate with the gun. A rocket can burn without an atmosphere, and the recoil of the rushing fumes will impel the car onwards." ”

“ It may even be possible to dispense with the gun, and travel in a locomotive car. Lord Kelvin has shown that if Lessage's hypothesis of gravitation be correct, a crystal or other body may be found which is lighter along one axis than another, and thus we may be able to draw an unlimited supply of power from gravity by simply changing the position of the crystal; for example, by raising it when lighter, and letting it fall when heavier. This form of 'perpetual motion' might be equally obtainable if Dr. Preston's [3] theory of an ether as the cause of gravity be true. ”

“ Just before the planet came up, and in the nick of time we could fire some rockets, and give the car a velocity of two or three miles a second in the direction of the planet's motion, so that he would overtake us, with a speed not over great to ensure a safe descent. ”

“ The atmosphere of the approaching planet would act as a kind of buffer, and the fall of the car could be further checked by our means of recoil, and also by a large parachute. We should probably be able to descend quite slowly to the surface in this way without damage; but in case of peril, we could have small parachutes in readiness as life-buoys, and leap from the car when it was nearing the ground."
G. "I presume you are taking into account the velocity of the planet in its orbit? That of the earth is 18 miles a second, or a hundred times faster than a rifle bullet ”

“ There are minds which can foresee what lies before us, and the march of science brings it within our reach. All or nearly all our great scientific victories have been foretold, and they have generally been achieved by more than one person when the time came. ”

“ In this way, by employing a series of guns, fired from each other in succession, we can graduate the starting shock, and give the bullet a final velocity sufficient to raise it against gravity, and the resistance of the atmosphere, which grows less as it advances, and send it away to the moon or some other distant orb. ”

“ However, instead of explosives we might employ compressed air to get the required velocity. In the air-gun or cannon, as you probably know, a quantity of air, compressed within a chamber of the breech, is allowed suddenly to expand behind the bullet and eject it from the barrel. ”

“ G. "So that it would not be absolutely necessary to give the projectile an initial velocity of five miles a second."
I. "No; and, besides, we are not solely dependent on the rocket. A jet of gas, at a very high pressure, escaping from an orifice into the vacuum or ether, would give us a very high propelling force. By compressing air, oxygen, or coal-gas (useful otherwise) in iron cylinders with closed vents, which could be opened, we should have a store of energy serviceable at any time to drive the car. ”