When I reached the cottage I spoke to Sam of my idea, and he agreed with an alacrity that surprised me. We tested the little model again, and he made revisions and alterations in the design. In a few days we began construction on the beach two hundred yards below the cottage. There was no lack of funds, and we pushed the work with all speed. We had a hundred workmen on the spot, and shops all over the country were busy turning out the parts and instruments which were rushed to us by air. I superintended the work myself, since Sam still spent most of his time in the little laboratory, working with that mysterious force. The Omnimobile, conceived and designed by Sam, would have been worthy of a Jules Verne's creative mind, and the great adventure into which it led us was far more weirdly amazing than any of those old wonder tales to which I had so passionately devoted myself. Without the hydrodyne, and a dozen other inventions of Sam's, the machine would have been impossible. Certainly it merited the name Omnimobile, for it was hard to imagine a place to which it would not be able to go. The vessel was of a tapering cylindrical shape, ten feet in central diameter, and forty-five feet long. The construction throughout was of the strongest modern alloys of aluminum and beryllium. The hull was ingeniously braced to enable it to withstand tremendous shocks or immense pressure. The ship carried an equipment of hydrodyne generators totalling more than five hundred thousand horse-power--an absurdly large power plant, it seemed to me. The machine had caterpillar tread for travel over-land or over the ocean floor, screws for propulsion over the water, vanes and rudders for diving, and another more unusual feature--rocket tubes to drive it through air or through empty space! They were of Sam's invention, and of novel design. They were loaded with water, and contained resistance coils through which a tremendous current could be sent from the generators, heating the special metal tubes to a temperature of some thousands of degrees, and converting the water into super-heated steam at enormous pressure, which, escaping at the nozzles, would propel the ship by reaction. According to Sam's figures, the machine should be able to hurl itself a hundred miles in ten minutes, but it seemed very unlikely that it would ever be able to develop the speed of seven miles per second required to get clear of the earth's gravitation.