Immediately Lord Kelvin was imitated by a dozen others. With what seemed very slight effort they projected themselves straight upwards, rising to a height of four hundred feet or more, and then slowly settling back again to the surface of the asteroid. The time of rise and fall combined was between three and four minutes.
On this little planet the acceleration of gravity or the velocity acquired by a falling body in one second was only four-fifths of an inch. A body required an entire minute to fall a distance of only 120 feet. Consequently, it was more like gradually settling than falling. The figures of these men of science, rising and sinking in this manner, appeared like so many gigantic marionettes bobbing up and down in a pneumatic bottle.
"Let us try that," said Mr. Edison, very much interested in the experiments.
Both of us jumped together. At first, with great swiftness, but gradually losing speed, we rose to an immense height straight from the ground. When we had reached the utmost limit of our flight we seemed to come to rest for a moment, and then began slowly, but with accelerated velocity, to sink back again to the planet. It was not only a peculiar but a delicious sensation, and but for strict orders which were issued that the electrical ships should be immediately prepared for departure, our entire company might have remained for an indefinite period enjoying this new kind of athletic exercise in a world where gravitation had become so humble that it could be trifled with.
While the final preparations for departure were being made, Lord Kelvin instituted other experiments that were no less unique in their results. The experience of those who had taken unpremeditated flights in elliptical orbits when they had run from the vicinity of the Martians suggested the throwing of solid objects in various directions from the surface of the planet in order to determine the distance they would go and the curves they would describe in returning.
For these experiments there was nothing more convenient or abundant than chunks of gold from the Martians' mine. These, accordingly, were hurled in different directions and with every degree of velocity. A little calculation had shown that an initial velocity of thirty feet per second imparted to one of these chunks, moving at right angles to the radius of the asteroid, would, if the resistance of an almost inappreciable atmosphere were neglected, suffice to turn the piece of gold into a little satellite that would describe an orbit around the asteroid, and continue to do so forever, or at least until the slight atmospheric resistance should eventually bring it down to the surface.
But a less velocity than thirty feet per second would cause the golden missile to fly only part way around, while a greater velocity would give it an elliptical instead of a circular orbit, and in this ellipse it would continue to revolve around the asteroid in the character of a satellite.
If the direction of the original impulse were at more than a right angle to the radius of the asteroid, then the flying body would pass out to a greater or less distance in space in an elliptical orbit, eventually coming back again and falling upon the asteroid, but not at the same spot from which it had departed.
So many took part in these singular experiments, which assumed rather the appearance of outdoor sports than of scientific demonstrations, that in a short time we had provided the asteroid with a very large number of little moons, or satellites, of gold, which revolved around it in orbits of various degrees of ellipticity, taking, on the average, about three-quarters of an hour to complete a circuit. Since, on completing a revolution, they must necessarily pass through the point from which they started, they kept us constantly on the qui vive to avoid being knocked over by them as they swept around in their orbits.
Finally the signal was given for all to embark, and with great regret the savants quitted their scientific games, and prepared to return to the electric ships.