"Hasn't it fallen out of sight yet?"
"No; it is not falling away swiftly as the air does. It is following the projectile! It is not gathering any air about it as you said it would. It does not quite keep up with us; but considering our speed, it is doing remarkably well!"
The doctor was not inclined to believe me until he had looked for himself. He watched and pondered for a minute or two. Then his surprise ceased, and he spoke in that assured way which always irritated me.
"Quite natural, after all," he said. "That biscuit can is made of thin sheet-iron with a surface coating of tin. The iron has become magnetized by induction, and the Earth repels the can just as it repels us. It will follow us to the dead-line, and probably on to Mars, unless the sheet-iron loses its polarization. If we had cast out a thing of solid iron, it would rush ahead of us, instead of falling a little behind, as this does, for it would have no dead weight to carry. But we could not put such a thing out of the rear end, for no force would make it fall that way. If we put it out of the forward port-hole, it would beat us in the race toward Mars."
I remarked to the doctor that the air-pump seemed to be incorrectly built, for its action was strangely difficult in the reverse manner that it should have been. The down strokes went by themselves with a quick snap, but the up strokes were as if against pressure, and the moment the handle was released it flew down again. He had not tested the pump at the surface, as it was of a well-known make, but it certainly seemed to work backwards. Moreover, the more nearly we had a compartment emptied of air, the more difficult the pumping should become, but here again the reverse seemed to be the case, for the longer we worked the easier the up strokes became.
The temperature of the projectile was still fairly comfortable, and the doctor allowed the condensed air to issue very slowly into the partial vacuum in his compartment until it produced a barometric pressure of twenty-seven. Then we pulled back the bulkhead, and when the new atmosphere had mixed with the old in my compartment, a pressure of twenty-eight resulted.
"That is about the way the barometer stands during tempests at sea," remarked the doctor. I could not notice much difference from the air we had previously had. Possibly it was fresher and slightly more exhilarating.
The effort at the pump had made us both hungry again, and I prepared from meat extracts a warm and rather thick gravy to put over the asparagus tips. I attempted to pour it, but it was so light that its sticky consistency prevented it from running. We had a hundred such examples daily of the changes which lack of weight caused in the simplest operations. With sandwiches made of biscuits and condensed meat, we eked out a luncheon. This must have been about noon, for when it was over I remember noticing that we no longer needed the gas in the compartment, for there was a gradually increasing mellow light outside.
"Are we already emerging from the shadow?" I inquired eagerly.
"No, not yet," replied the doctor. "But we are now entering its illuminated core. I must prepare to photograph the strange appearance of the Sun that we shall see presently."