David Bushnell And The First American Submarine

DAVID BUSHNELL'S submarine, the Turtle, the prototype of all modern submarines, was launched at Saybrook, Connecticut, in 1775, and attempted her first torpedo attack upon an enemy warship in September, 1776. However, she was far from being the first submarine. Although an obscure reference to a diving vessel is to be found in the manuscripts of Leonardo da Vinci, the premier document in the history of the submarine is Article 18 of William Bourne's Inventions or Devises, published in London in 1578. Bourne, a self-taught mathematical genius, was an innkeeper and a jurat (alderman) of Gravesend, and at one time had been a gunner under Admiral Sir William Winter. He was the author of several books that exhibit every indication of being the product of experience rather than of mere theorization; but, since he wrote during the transitional period of our language, and was not even master of the prose of his time, his style is graceless and confusing. It is preferable, therefore, to translate the tortuously involved phraseology of his account into modern English rather than to present it verbatim.

First he postulates that if the weight of an object is greater than the weight of the water that it displaces, it sinks, and that if the reverse is true, it floats. He goes on to say that if the displacement of an object is increased or decreased, while its weight remains constant, it can be made to sink and rise at will. After enunciating his theory, Bourne describes the manner in which it was carried into practice.

A small boat was heavily ballasted, and a watertight deck fitted directly over the ballast. The vessel was then completely decked over, presumably at gunwale height, leaving sufficient room between the decks for a man to stand upright. She was also fitted with a watertight hatch and a hollow mast which conducted fresh air into the craft. Her hull, for the distance between the two decks, was bored full of holes. Then two movable bulkheads, running horizontally from stem to stern, were constructed inside the submarine, one alongside the starboard side of the hull, the other alongside the port. These bulkheads were rendered watertight with leather, and could be moved inward for a short distance by transverse screw jacks. The resultant intervening spaces between the hull and each bulkhead formed a ballast tank on either side of the craft. The water entered the ballast tanks when the bulkheads were moved inward, and it was expelled when each was forced back to its original position, thus submerging the vessel and bringing her to the surface.¹

A century and a half after Bourne's death, Nathaniel Symons, a Devonshire carpenter, constructed and successfully operated, circa 1729, a diving boat that was almost identical with that of Bourne. Neither of the submarines could be navigated; in fact, they were capable of no more than vertical movement, that is to say, of being submerged and brought to the surface.

The next inventor who steps upon the scene, as Robert Boyle wrote in 1660, is "that deservedly famous mechanician and chemist, Cornelius Drebbel, who . . . is affirmed to have contrived for the late learned King James, a vessel to go under water, of which trial was made in the Thames with admirable success. . . ."²

Cornelius Drebbel was born in 1572 at Alkmaar, Holland, and came to England in 1604. He attracted the favorable notice of King James I. Drebbel has been called a charlatan, an empiric, and an alchemist, but whatever his reputation, his submarine is the first of which there is any extensive documentation. Georg Harsdorffer, the German poet, a friend of Drebbel and a possible eyewitness to his experiments, says that while Drebbel was watching some Thames fishermen towing baskets of fish behind their boats he noticed that the displacement of the boats increased and decreased as the towropes tautened and slackened. It occurred to Drebbel that a small boat could be ballasted until she had only a small amount of buoyancy, and that she could then be submerged by means of oars. Harsdorffer adds that two boats, decked over and covered with greased hide to make them watertight, were constructed in England, and that King James is supposed to have traveled in one in company with several other passengers. On this occasion the submarine was propelled by twelve oarsmen, and during a voyage lasting several hours she was kept at a depth of from 12 to 15 feet below the surface. Whether King James, who lived in constant danger of assassination, would have risked his life in that manner is questionable. Even more doubtful is the statement that the boat could be submerged to 15 feet; it is probable that she ran awash most of the time, and that occasionally she made short, porpoise-like dives.

Boyle's explanation of how the craft was supplied with fresh air is suitable to Drebbel's reputation as an alchemist. Drebbel, Boyle observes, conceived that when a certain quintessence or spirituous part of the air is consumed, the remaining grosser body of the air is unable to cherish the vital flame that resides in the heart. Therefore, when he perceived that the finer and purer part of the air was consumed or overdogged with the respirations and steams of those that went in his boat, he would, by unstopping a vessel full of some chemical liquor, speedily restore to the troubled air such a proportion of vital parts as would make it again fit for respiration.³

Another seventeenth-century scientist, the Abbe d'Hautefeuille, suggested, in a pamphlet published in 1680, that it was more reasonable to suppose that Drebbel ventilated the submarine by means

of a bellows with two valves and two tubes resting on the surface of the water, the one sending down air, the other sending it back. By speaking of a volatile essence which restored the nitrous parts consumed by respiration, Drebbel wished to disguise his invention and prevent others from finding out its real nature.⁴

In the absence of any definite information regarding the exact dates of Drebbel's voyages, we may assign his experiments approximately to the year 1625, when he and his submarine were the subject of a few ironic lines in Ben Jonson's comedy The Staple of News. His boat is supposed to have been used in the Duke of Buckingham's unsuccessful expedition to La Rochelle in 1628, and from the Calendar of State Papers, Domestic 1661-1662, we learn that 28 years after Drebbel's death his son Jacob and his son-in-law, Johannes Kuffier, requested a government "trial of their father Cornelius Drebbel's secret of sinking or destroying ships in a moment; and if it succeed, for a reward of £10,000."⁵ The reward, however, was never paid and nothing more is known of Drebbel's submarine.

In 1634, a French priest, Mann Mersenne, a disciple and a close friend of Descartes, invented a submarine that was to have had a metallic, pisciform hull. Mersenne recommended that all future submarines should be of the same shape in order to offer the least resistance to the water; his own boat was to have been equipped with ventilating machines, illuminated by phosphorescent substances, and propelled by oars. He intended that she (like Simon Lake's Argonaut in a later age) roll along the sea bottom on wheels. Her armament was to have consisted of two large  cannon, that, like Robert Fulton's "Columbiads," were to have been fired under water at the bottom of an enemy ship. The gunports were to have been closed with a plug valve against which the muzzle of each cannon was to have been tightly fitted. The plug was to have been withdrawn at the moment of firing and it was to have fallen back into place automatically as the gun recoiled. Needless to say, this submarine was never constructed.

Drebbel's experiments, and the writings of Mersenne, stimulated the active, inquiring mind of John Wilkins, Bishop of Chester, to theorize upon submarine navigation. Wilkins, a man of great intellectual attainments, never quite achieved the stature of a philosopher, nor did his vessel ever see form except in the pages of his book, Mathematical Magick (London, 1648). His remarkable essay on the submarine fluctuates between genuine speculative thought, and the unbridled vaporings of an imagination allowed to run riot. Wilkins wrote at great length "concerning the possibility of framing an ark for submarine navigations," and his conclusions are especially interesting:

(1) 'Tis private; a man may thus goe to any coast of the world invisibly, without being discovered or prevented in his journey.
(2) 'Tis safe; from the uncertainty of Tides, and the violence of Tempests, which do never move the sea above five or six paces deep. From Pirates and Robbers which doe so infest other voyages; From ice and great frosts, which doe so much endanger the passages towards the Poles.
(3) It may be of very great advantage against a Navy of enemies, who by this means may be undermined in the water and blown up.
(4) It may be of special use for the relief of any place that is besieged by water, to convey unto them invisible supplies: and so likewise for the surprise of any place that is accessible by water.
(5) It may be of unspeakable benefit for submarine experiments and discoveries: as . . . the nature and kinds of fishes, the several arts of catching them, by alluring them with lights, by placing divers nets about the sides of this Vessell . . . .
All kinds of arts and manufactures may be exercised in this Vessel . . . . Severall Colonies may thus inhabit, and having their children born and bred up without the knowledge of land, who could not chose but be amazed with strange conceits upon the discovery of this upper world.⁶

In the latter part of the eighteenth century a Frenchman named Dionis built a submarine that was propelled by eight oars. Further constructional details are lacking, but it is reported that on May 28, 1772, she carried ten people on a submerged voyage of 15 miles in the Bay of Biscay, during which she is said to have remained below the surface for 41 hours. I assume that she must have been quite similar to Drebbel's boat, and that her submerged run actually amounted to no more than a succession of plunging dives, each of a few minutes' duration.

An interesting quasi-submarine was invented in 1774 by an Englishman named Day, who had a watertight cabin constructed in the hold of a 50-ton sloop. This cabin, which was 12 feet long, 9 wide, and had 8 feet of headroom, was strongly reinforced to withstand the pressure of the water. A square scuttle was cut in the top of the cabin and to this was fitted a hatch cover that, on being screwed down against a flannel gasket, sealed the opening. The vessel had 10 tons of internal ballast, and 20 tons more were attached to the outside of the hull by means of four ring-bolts that could be released from within the cabin. She was submerged by allowing the hull to fill with water, and Day believed that she would rise to the surface when the external ballast was dropped. Like the submarines of Bourne and Symons, Day's boat could not be navigated. He planned, as part of a wager, to do no more than sink her "under water . . . live therein for a certain time, and then, by his own means only, bring himself to the surf ace."⁷ On June 28, 1774, the vessel was submerged to a depth of 22 fathoms in Plymouth Sound. She sank readily enough, but failed to reappear. Day's wooden cabin, no matter how strongly it may have been buttressed, was undoubtedly crushed before the submarine ever reached bottom. The wreck was never recovered.

The designers of the early submarines found it impossible to meet all of the four basic requirements of a submarine: submergibility, maneuverability, adequate air supply, and the ability to take offensive action. While the depth to which Bourne's boat could be submerged was limited to the height of the hollow mast, she could remain on the bottom for considerable time. However, because of her lack of maneuverability her usefulness, except as a curiosity, was nil. Drebbel's craft could be navigated almost as easily as a rowboat, and she was probably supplied with air through a tubular connection with the surface; still, she could not be submerged to any great depth, nor for any length of time, and she did not, so far as we can determine with any certainty, carry any weapon of offense. The other inventors, Mersenne and Wilkins, for instance, who solved all four problems, did so only nebulously.

The difficulties that were inherent in the construction of a torpedo-carrying submarine, the subsurface course of which could be accurately controlled, remained insurmountable until a Yale undergraduate named Bushnell invented the first "modern" submarine.
David Bushnell was born at Saybrook, Connecticut, circa 1742. He was remembered in later years by his boyhood friends as a shy lad who spent most of his time working on his father's farm, and who devoted his leisure hours to reading. Bushnell matriculated at Yale in 1771, and while still a freshman demonstrated to several members of the faculty that gunpowder could be exploded under water, a fact which had theretofore been doubted.

During his course at Yale, Bushnell, who stood high in mathematics, appears to have given a certain amount of thought to the invention of a submarine. Then it would seem that in the summer of 1775 it occurred to him that his discovery that gunpowder would explode under water might be useful in breaking the British blockade of Boston. Having concluded that even the most powerful ship of war would be vulnerable to torpedo attack, and that the most effectual way to convey a torpedo under an enemy vessel was by means of a submarine, Bushnell, in a characteristically Yankee manner, immediately set to work to build a submarine.

The boat was shaped like a top; the seams were well caulked and the hull, which was made of oak timbers 6 inches in thickness, was bound with iron bands and thoroughly coated with tar to make it as watertight as possible. Bushnell states that the Turtle, which measured 71- feet in length and 6 feet in depth, contained enough air to last, without replenishment, for half an hour. He describes her as bearing

some resemblance to two upper tortoise shells of equal size, joined together; the place of entrance into the vessel being represented by the opening made by the swell of the shells, at the head of the animal. . . . The internal shape of the vessel, in every possible section of it, verged towards an ellipsis, as near as the design would allow, but in every horizontal section, although elliptical, yet as near to a circle as could be admitted.⁸

A beam was fitted transversely into the interior of the submarine for use as a seat, and to reinforce the sides against the pressure of the water during a deep dive. The hatchway was elliptical and so small as to barely admit a man. Sunk into the wood of the hull at the hatch was a broad iron band that acted as additional support against the pressure of the water. Hinged to the band was a brass hatch cover that could be screwed down until it was quite watertight. This assembly constituted the conning tower and projected about 6 or 7 inches above water when the Turtle was in surface trim. In the collar of the hatch cover there were six glass ports, about the size of a half dollar, through which observations were made. On a clear day, the light admitted by these ports was sufficient to permit the operator to see his navigating instruments perfectly. The instruments, a depth gauge and a compass, were illuminated with a phosphorescent wood known as "fox-fire" so that they would also be visible in the dark. The depth gauge, a glass tube 18 inches long and 1 inch in diameter fastened in an upright position with its upper end sealed and its lower open to the sea, bears a close resemblance to present-day glass sounding tubes. In it was a cork float that rose about one inch as the submarine descended about one fathom. "By the light of the phosphorus the ascent of the water in the gauge was rendered visible, and the depth of the vessel under water ascertained by a graduated line."⁹ Two air pipes projected through the conning tower hatch and a ventilator within the vessel drew fresh air down one pipe and expelled the foul air through the other. These pipes were capped with valves that closed automatically when the boat submerged. In the sides of the hatch cover there were also three small portholes which were covered with watertight deadeyes. To ventilate the submarine rapidly when she was on the surface, the operator usually unscrewed the deadeyes in preference to using the air pipes.

The submarine was ballasted by 700 pounds of lead, 200 of which could be lowered by a small winch to a depth of 40 or 50 feet below the vessel so that, in the event that the pumps choked, she could instantly be brought to the surface. In addition to acting as a safety device, this detachable ballast was also used as an anchor. Due to her elliptical form and the weight of the ballast, the Turtle had a low center of gravity, and whether running submerged or on the surface, she was a very stable craft. She was propelled in a horizontal plane, ahead and astern, by a screw propeller 12 inches long and 4 broad that was fitted to a shaft at the bow, and revolved by a crank that could be turned by hand or by a foot treadle, as required. The screw propeller is supposed to have been invented early in the nineteenth century by Sauvage; although Thomas Jefferson surmised that Bushnell was really entitled to the credit for the invention, Bushnell himself makes no claim as to the originality of the device, and as Commander Sueter has pointed out, Robert Hooke (with whose works Bushnell was doubtless familiar) discussed the subject in 1680.

In the bottom of the boat there was a brass flood valve which was somewhat similar to the Kingston valves on the submarines of today. Apparently the Turtle had no separate ballast tank, for, to submerge her, the operator depressed the valve with his foot and the submarine gradually descended as the water flooded her bilges. If too much water had been admitted, the excess was ejected by means of two force pumps; to bring her to the  surface, the operator simply pumped her dry.

The design of Bushnell's Turtle was predicated upon the theory—now known to be fallacious, but which was accepted by the physicists of the time—that if the weight of an object were exactly equal to the weight of the water that it displaced, it would float in a static position beneath the surface. Actually, it is impossible to strike a perfect balance between a submarine and the surrounding water. In the modern submarine, no attempt is made to do so; under normal conditions, a certain amount of buoyancy is retained at all times and the boat is literally forced under the surface by her hydroplanes. Bushnell knew nothing of the hydroplane but he achieved the same effect by the use of a vertical propeller, slightly smaller than the previously mentioned horizontal one, which was fitted to a shaft in front of the conning tower. After a semi-equilibrium had been obtained in the Turtle, the operator could easily move her upwards, or downwards, and as she traveled her course, he must have been able to keep her at a fairly constant depth by working the horizontal propeller with the treadle and simultaneously cranking the vertical one with his hand. Of course, when she was safe from observation, the Turtle was allowed to run with the conning tower out of water.

Every opening was well secured, Bushnell writes. The pumps had two sets of valves, and the flood valve opening was covered with a perforated metal plate to keep it from being obstructed by sea weed. The tiller, which was just long enough to reach under the operator's left arm, and the various shafts and tubes that passed through the hull of the boat were fitted exactly to watertight joints that were kept full of oil to prevent rust and leakage. He adds that:

Particular attention was given to bring every part, necessary for performing the operations, both within and without the vessel, before the operator, and as conveniently as could be devised; so that everything might be found in the dark. . . and nothing required the operator to turn to the right hand, or to the left, to perform any thing necessary.¹⁰

The "magazine" or torpedo—an eggshaped oak casing containing 150 pounds of gunpowder (more than enough to sink any ship then afloat) and a simple clockwork detonator—was carried abaft the conning tower and just above the rudder. It was fastened to the hull by a bolt that also acted as a stop on the movement of the clock. Not until the very moment that the operator withdrew the bolt and released the torpedo was the firing mechanism set in motion; after running for about an hour it unpinioned a flint gunlock and set off the powder.

A vertical shaft passed through the forepart of the conning tower; its inner end terminated in a crank, and the outer end was tipped with a detachable woodscrew to which was attached a short length of strong line that ran to the torpedo. Bushnell intended that the Turtle be maneuvered under a warship and that the screw be driven into her hull. Whereupon, after the shaft had been disengaged from the screw, the torpedo was to be cast off and left to explode against the side of the ship after the submarine had got clear.

"The simplicity, yet combination discovered in the mechanism of this wonderful machine," exclaims General Humphreys, one of Bushnell's staunchest supporters, "were acknowledged by those skilled in Physicks, and particularly Hydraulicks, to be not less ingenious than novel."¹¹

The submarine was completed some time before November, 1775. Due to ill health, Bushnell himself was unable to operate her and he prevailed upon his younger brother, Ezra, to do so. Many practice dives were made in the Connecticut River, and, "in the first essay with the submarine vessel," Bushnell states, "I took care to prove its strength to sustain the pressure of the incumbent water, when sunk deep, before I trusted any person to descend much below the surface." Until a man was completely familiar with the operation of the submarine, Bushnell continues, his first dives were made while the Turtle was secured by a towline to a boat on the surface. "After that, I made him descend and continue at particular depths, without rising or sinking, row by the compass, approach a vessel, go under her and fix the woodscrew . . . into her bottom, &c., until I thought him sufficiently expert to put my design into execution." Ezra Bushnell "was very ingenious and proved himself a master of the business.”¹²

In spite of the fact that Bushnell tried to conduct his experiments in secret, his activities were common gossip in the villages along the Connecticut River. And during the latter part of 1775 and the early months of 1776, one of his friends, Dr. Benjamin Gale, of Killingworth, was corresponding with Silas Deane, a delegate to the Continental Congress at Philadelphia, revealing Bushnell's plans, describing the submarine in detail, and discussing the inventor's difficulties in perfecting her. Since many of Gale's letters were intercepted, copied, and circulated by Sheader, the tavern-keeper, and postmaster of Killingworth, it is not surprising that on November 16, 1775, Governor Tryon of New York informed Vice Admiral Molyneux Shuldham, Commander in Chief of the British Squadron in North America, that:

The great news of the day with us is now to Destroy the Navy, a certain Mr. Bushnell has completed his Machine, and has been missing four weeks, returned this day week.

It is conjectur'd that an attempt was made on the Asia, but proved unsuccessfull—Returned to New Haven in order to get a Pump of a new Construction which will soon be completed,—When you may expect to see the Ships in Smoke.¹³

(An abortive attack may have been made on the Asia while she was at Boston, but Bushnell does not mention it.)

After laying his plans before Governor Trumbull and the Council of Safety of the State of Connecticut on February 2, 1776, Bushnell was urged to continue his experiments "with every expectation of proper notice and reward."¹⁴

During the Revolution no fewer than 350 armed vessels of various kinds and classes were fitted out in Connecticut. This was a great strain on the resources of so small a state, and inasmuch as the Turtle was a radical departure from all recognized types of naval craft, it is not difficult to understand why the Governor and the Council were reluctant to do more than offer the inventor encouragement. The submarine was brought to the attention of Washington, Jefferson, Franklin, and others, and although Bushnell later received small sums from time to time to help defray the expense of operating her, she cost him every cent he had.

General Howe, despite his victory at Bunker Hill, soon found his position at Boston untenable and on March 17, 1776, withdrew to Halifax. Then, on June 10, greatly reinforced by fresh troops from England, he sailed for New York, disembarking his army at Staten Island on July 5. American privateers were harrying British commerce and capturing even the supply ships of the Royal Navy, yet it was impossible to oppose this move with an American naval force worthy of the name, and attempts were made to annoy the British with a few fire rafts and armed sloops, under the command of General Israel Putnam.

Bushnell seems to have been confident that his submarine would prove to be far more than a mere annoyance. He explained his designs to General Washington, who was favorably impressed with Bushnell, but not with the Turtle. Bushnell, Washington declared in 1785,

is a man of great mechanical powers, fertile of inventions and master of execution. He came to me in 1776, recommended by Governor Trumbull and other respectable characters, who were converts to his plan. Although I wanted faith myself, I furnished him with money and other aids to carry his plan into execution.¹⁵

Bushnell selected H.M.S. Eagle, the 64-gun flagship of Admiral Lord Howe, as the target of the torpedo. Unfortunately, his brother Ezra fell ill and was unable to operate the submarine. David Bushnell applied to General Parsons, of the Connecticut Militia, for three volunteers "to go and learn the ways and mystery of this new machine."16 After several trial runs in Long Island Sound, Bushnell chose Sergeant Ezra Lee, evidently the most competent of the three, to pilot the submarine. Then it was discovered that she required several alterations, which, it seems, could only be made at Saybrook. After eight or ten days of delay Bushnell and Lee returned to New York to find that Howe's troops had occupied Governor's Island and had driven Washington out of Long Island.

It was now the latter part of August. Washington was to evacuate his Brooklyn lines on the 29th, Howe was to capture New York City on September 15, and on the 16th, after the affair of Harlem Heights, all of Manhattan was to fall into the hands of the English. The military situation was changing so rapidly that, if the submarine were to be of any value in the campaign of 1776, every hour was precious.

The British squadron, including a large number of transports, lay to the north of Staten Island. Bushnell's eyes were still on the Eagle. None of the harbors of Long Island was available as a base and the attack had to be launched from Whitehall—a comparatively distant point. By dint of hard cranking, a man could propel the Turtle for a short spurt at the rate of 3 knots. Her normal rate of speed must have been about 2 knots, and her air was sufficient for only 30 minutes; as a result, she probably could not travel more than a mile, if that, without having to come to the surface. It was unsafe, therefore, to take her out except on a moonless night since she might have been observed by her quarry. In addition, it was difficult to manage her in a swell or in a strong tide, so that Bushnell and Lee had to wait until conditions were favorable before risking an attack.

After a few days a favorable night arrived, and on September 6, 1776, at eleven o'clock, Sergeant Lee set off from the city. He informs us that:

the whaleboats towed me as nigh the fleet as they dared and then cast me off. I however hove about and rowed for 5 glasses by the ships' bells before the tide slackened so that I could get alongside a man of war which lay above the transports. The moon was about 2 hours high and the daylight about one. When I rowed under the stern of the ship I could see the men on deck and hear them talk. I then shut down all doors, sunk down and came up under the bottom of the ship. Up with the screw against the bottom but found it would not enter. I pulled along to find another place, but deviated a little to one side and immediately rose with great velocity and came above the surface 2 or 3 feet between the ship and the daylight, then sunk again like a porpoise. I hove about to try again, but on further thought I gave out, knowing that as soon as it was light the ships' boats would be rowing in all directions, and I thought the best generalship was to retreat as fast as I could, as I had 4 miles to go before passing Governor's Island. So I jogged on, as fast as I could, and my compass being then of no use to me, I was obliged to rise up every few minutes to see that I sailed in the right direction, and for this purpose keeping the machine on the surface of the water and the doors open. I was much afraid of getting aground on the Island, as the tide of the flood set on the north point.

While on my passage up to the city, my course, owing to the above circumstances was very crooked and zig-zag, and the enemy's attention was drawn towards me from Governor's Island. When I was abreast of the fort on the Island, 300 or 400 men got up on the parapet to observe me; at length a number came down to the shore, shoved off in a 12 oar'd barge with 5 or 6 sitters and pulled for me. I eyed them, and when they had got within 50 or 60 yards of me I let loose the magazine in hopes that if they should take me they would likewise pick up the magazine, and then we should all be blown up together. But as kind Providence would have it, they took fright and returned to the Island to my infinite joy. I then weathered the Island, and our people seeing me, came off in a whaleboat and towed me in. The magazine, after getting a little past the Island, went off with a tremendous explosion, throwing up bodies of water to an immense height.¹⁷

The only tangible result of this attempted attack was that the British ships cut their cables in alarm at the explosion, drifted down the Bay with the ebbing tide, and anchored off the southern end of Staten Island.

Before an opportunity presented itself for a second raid, the Continental forces evacuated Manhattan. Bushnell and Lee loaded the Turtle on a sloop and retreated with Washington's army to Fort Lee. While they were there Ezra Lee made an unsuccessful attack, of which no details are available, on a British ship. Later, when a British frigate came up the Hudson and dropped anchor off Bloomingdale, Bushnell and Lee, undaunted and not at all disheartened by previous frustrations, decided to torpedo her. Sergeant Lee attempted to go under the vessel's stern and attach the torpedo to her hull, close to the water line; unluckily, he was discovered by the watch. In trying to dive under the ship he descended too deeply and the submarine was swept away by the tide. Soon after that, on October 9, three British ships, two 40-gunners and the frigate, with two or three tenders, stood up the river. After being subjected to a brisk yet futile cannonade from Fort Washington and Fort Constitution, they engaged the small American naval force that was present. The American flotilla—a few galleys, some small craft and two schooners—was routed in short order. The schooners were run ashore at Phillips' Mills, two of the galleys were beached near Dobbs' Ferry, and the sloop carrying the submarine was sunk. Bushnell and Lee managed to escape; they subsequently recovered the Turtle but she never made another raid.

The failure of Bushnell's submarine was due almost entirely to the inexperience of the operator. After being deprived of the services of his brother Ezra, who had spent months learning how to control the submarine, Bushnell never again had sufficient time and money to train another operator properly. Mechanically, the Turtle was sound. "I . . . thought, and still think," said Washington in 1785, "that it was an effort of genius, but that too many things were necessary to be combined, to expect much from the issue against an enemy, who are always upon guard.”¹⁸ In 1813, Thomas Jefferson was more enthusiastic about the submarine, and wrote that she "was excellently contrived, and might perhaps, by improvement, be brought into real use. . . . It would be to the United States the consummation of their safety.”¹⁹ And as late as 1875, Lieutenant F. M. Barber, U. S. Navy, expressed the opinion that the Turtle "seems to have been the most perfect thing of its kind that has ever been constructed, either before or since the time of Bushnell.”²⁰

Even though Bushnell's original plans had miscarried, he was far from being discouraged. His belief that the torpedo had a place in naval warfare remained unshaken. Having been forced to give up the use of the submarine, he modified the torpedo so that it could be towed at the end of a long line behind a whaleboat: the device, weighted with lead, was suspended below a wooden float and a toothed wheel was so arranged that when it came in contact with the side of a ship it actuated a clockwork detonator, which ran for a few minutes before exploding the powder.

On April 22, 1777, he exhibited the invention in its altered form to the Governor and the Council of Safety of Connecticut. Evidently Trumbull and his Council had far more faith in the new torpedo than they ever had in the submarine, for they "gave him an order on officers, agents, and commissaries to afford him assistance of men, powder, lead, &c., as he might want, delivered to him without stint.”21

On the night of August 13, 1777, Bushnell tried to draw a torpedo against the side of H.M.S. Cerberus, which lay at anchor, in company with a schooner, to the westward of New London, in Blackpoint Bay. At about 11:00 P.M., while Bushnell sat in darkness, guiding the torpedo from a whaleboat, the men on the schooner caught sight of the towline and hauled it in. They heaved the torpedo up on deck, and not realizing what it was, were examining it too curiously when it exploded, killing three men and blowing a fourth man overboard. The frigate was not damaged by the explosion.

According to the report sent to Admiral Sir Peter Parker by J. Symons, Commodore of the British Squadron off New London, the seamen set the notched wheel

a-going, which it did with great ease backwards and forwards, and during their looking at it, which was about five minutes from the time of its being first put in motion, it burst. Upon examining round the ship after this accident, we found the other part of the line on the larboard side . . . which I ordered to be cut away immediately, for fear of hauling up another machine . . . As the ingenuity of these people is singular in their secret modes of mischief, and as I presume this is their first essay, I have thought it indispensibly my duty to return and give you the earliest information of the circumstances, to prevent the like fatal accident happening to any of the advanced ships that may possibly be swifted in the same manner: and to forbid all seamen from attempting hauling the line, or bringing the vessel near the ship as it is filled with that kind of combustible that burns through in the water.²²

In the latter part of the year 1777, Bushnell prepared about 40 floating mines at Burlington, New Jersey. These mines were no more than powder kegs, fitted with gunlocks, and set to explode on being jarred. At Christmas time, 1777, the mines were set adrift in the Delaware. Bushnell depended upon the tide to carry them down river and among the British ships at Philadelphia. He was not very familiar with the river and depended upon a guide who turned out to be incompetent; the kegs were released much too far—more than a mile—above Philadelphia. They were separated by ice and so delayed that the first mine did not arrive off the city until January 5, 1778. It blew up a small boat, killing two boys who had tried to haul it out of the water, and alarming the British to the extent that the banks of the river were lined with soldiers who had orders to fire at every object of suspicious appearance. Aside from these comparatively minor results, the mines were a complete failure and served mainly to amuse the Colonials who watched the Redcoats keep up a continuous fusillade for 24 hours.

After this fiasco Bushnell dropped from sight, so far as the records are concerned, and we know nothing definite about his activities until May, 1779, when a small party of British landed from a whaleboat at Middlesex, Connecticut, capturing Bushnell and two other Americans. In a dispatch dated May 7, Major General Putnam informed General Washington that as Bushnell, "who was in prosecution of his unremitting endeavours to destroy the enemy's shipping, is personally known to very few people, it is possible that he may not be discovered by his real name or character and may be considered of less importance than he actually is.”²³

As Putnam expected, Bushnell was not recognized and a few days later he was exchanged as a civilian. When Bushnell was released, his good friend Governor Tiurnbull "pursued him with . . . kindness and encouragement, until, with a well-timed and warm hearted letter to General Washington, he secured him to a permanent and honourable position as Captain in a Continental Corps of Sappers and Miners."²⁴

Bushnell's active connection with submarine warfare ceased when, on August 2, 1779, he was appointed a captain-lieutenant in the Corps of Sappers and Miners (the forerunner of the Corps of Engineers, U. S. Army). In June, 1781, he was promoted captain and took part in the siege of Yorktown. By June, 1783, he had risen to the command of the Corps, which was then stationed at West Point. He served with the Continental Army until the last troops were mustered out in November, 1783, at which time he accepted a commutation of five years' pay in lieu of half-pay for life.

Upon leaving the Army he sailed for France, and was supposed to have been killed in the French Revolution, but in 1795, he returned to America, and under the assumed name of "Dr. Bush," settled in Georgia. Through an old college friend and fellow soldier, Abraham Baldwin, Bushnell became the head of a private school in Columbia County. He later practiced medicine in Warrenton, where he died, unmarried, in 1826 at the age of eighty-four. His estate passed to the children of his deceased brother, Ezra; included in the bequest was "some curious machinery, partly built, which had been viewed by several gentlemen, none of whom . . . [were] . . . able to determine what it might have been, had it been completed."²⁵ It is not at all improbable that this was a model of a submarine or a mine and that Bushnell retained his interest in submarine warfare until the day of his death.

The advances that have been made in submarine warfare since the time of Bushnell have been in the nature of technological improvements. The basic inventions were his, and although it is true that he achieved but little practical success, success in war cannot always be measured by the number of battles won, ships sunk, and men killed. Tactically, Bushnell's torpedoes and mines were a failure; strategically, they were far more successful than Bushnell or anyone else realized at the time. Even though he did not sink a single ship of any consequence, the imponderable factor of the moral effect of Bushnell's activities cannot be underestimated: he gave the commanders of the British ships a feeling of insecurity and an anxious awareness of constant danger which deterred them from executing many coastwise movements and otherwise employing preponderant British sea power to greater advantage. And that, from the perspective of this century, is recognizable as a victory of no small value, even if it was not of decisive importance.