When Jules Verne’s Twenty Thousand Leagues Under the Sea appeared in 1869, it helped advance beyond the realm of dreams an idea which had been in the minds of men for well over a thousand years.

Alexander of Macedon is reputed to have used underwater divers at the siege of Troy in 334 B.C. At about the same time, we are told, he had a glass barrel built (left), in which he had himself lowered to the bottom of the sea “to defy the whale.” But the first account of underwater craft which has the ring of authenticity is dated 1505. Olaus Magnus, Bishop of Uppsala in Sweden, tells of seeing in the cathedral of Asloe two “leathern boats” used by pirates of “Gruntland” to attack merchant ships from the surface or from beneath it.

These and a few other submarines recorded over the next two hundred-odd years were all prologue to the serious work of the last three decades of the eighteenth century, when three remarkable inventors were at work: an Englishman named Day (history has nowhere recorded his first name) and two Americans, David Bushnell and Robert Fulton.

Day’s diving vessel (right)—it was no submarine but, oddly enough, a sloop—contained an airtight, watertight chamber and carried thirty tons of stone ballast. When the day of its test came, in June of 1774 in Plymouth Sound, thirty tons proved insufficient to force the boat underwater, and Day had more stones heaved in until the sloop started to sink. He forgot one thing: he would have no way of disposing of the extra stones from his position inside the chamber. Once he had submerged, there was no way of communicating with Mr. Day.

An acquaintance, Dr. N. D. Falck, was in London at the time and reasoned that as long as Day was inside the chamber, preserved by the underwater cold and inaccessible to hungry fish, he had a good chance of being resuscitated. Accordingly the good Doctor removed himself at leisure to Plymouth in July and put in motion a rescue program which continued, without result, until October. Then the weather turned bad, and, as Falck noted, “My private affairs required my attention at home.” He went back to London, expecting to return to Plymouth to bring up the unfortunate Mr. Day; but he never did. Nor was Day ever found.

In the summer of 1776 David Bushnell of Connecticut launched the first true submarine (left) of which we have real knowledge. Called the Turtle because it looked like two turtle shells fastened together and floating tail down in the water, it was just large enough to hold a man and the simple instruments necessary for its manipulation.

One night in August, 1776, in New York harbor, the Turtle was towed out as far as safety permitted, the hatch was closed, and an Army volunteer named Ezra Lee began the lonely