Did Van Drebel anticipate by one hundred and fifty years the discovery of oxygen: the life-giving “Quintessence” of air? Even if he did, it is incredible that he should have found a liquid, utterly unknown to modern chemistry, capable of giving off that gas so freely that a few gallons would restore the oxygen to a confined body of air as fast as fifteen or twenty men could consume it by breathing. Perhaps his “Chymicall liquor” instead of producing oxygen directly, increased the proportion of it in the atmosphere by absorbing the carbonic acid gas.
The Abbé de Hautefeullie, who wrote in 1680 on “Methods of breathing under water,” made the following shrewd guess at the nature of the apparatus:
“Drebel’s secret was probably the machine which I had imagined, consisting of a bellows with two valves and two tubes resting on the surface of the water, the one bringing down air and the other sending it back. By speaking of a volatile essence which restored the nitrous parts consumed by respiration, Drebel evidently wished to disguise his invention and prevent others from finding out its real nature.”
It is a very great pity that we know no more about these earliest submarines. Cornelius Van Drebel died in 1634, at the age of sixty-two, without leaving any written notes or oral descriptions. We must not think too hardly of this inventor of three centuries ago, unguarded by patent laws, for making a mystery of his discoveries. He had to be a showman as well as a scientist, or his noble patrons would have lost all interest in his “ingenious machines,” and mystery is half of the showman’s game. Besides his “eel-boats,” Van Drebel is said to have invented a wonderful globe with which he imitated perpetual motion and illustrated the course of the sun, moon, and stars; an incubator, a refrigerator, “Virginals that played of themselves,” and other marvels too numerous to mention. Half scientist, half charlatan, wholly medieval in appearance, with his long furred gown and long, fair beard, Cornelius Van Drebel marches picturesquely at the head of the procession of inventors who have made possible the modern submarine.
Eighteen years after Van Drebel’s death, a Frenchman named Le Son built a submarine at Rotterdam. This craft, which is usually referred to as the _Rotterdam Boat_, was 72 feet long, 12 feet high, and of 8 foot beam. It was built of wood, with sharply tapering ends, and had a superstructure whose sloping sides were designed to deflect cannon balls that might be fired at the boat while traveling on the surface, while iron-shod legs protected the hull when resting on the sea bottom. A single paddle-wheel amidships was to propel the boat,--just how, the inventor never revealed. Like so many other submarines, the _Rotterdam Boat_ was built primarily to be used against the British fleet. But it failed to interest either the Dutch or French minister of marine, and never went into action.