Archibald Williams

The introduction of torpedoes for use against an enemy’s ships below the waterline has led by natural stages to the evolution of a vessel which may approach unsuspected close enough to the object of attack to discharge its missile effectively. Before the searchlight was adopted a night surprise gave due concealment to small craft; but now that the gloom of midnight can be in an instant flooded with the brilliance of day a more subtle mode of attack becomes necessary.

Hence the genesis of the submarine or submersible boat, so constructed as to disappear beneath the sea at a safe distance from the doomed ship, and when its torpedo has been sped to retrace its invisible course until outside the radius of destruction.

To this end many so-called submarine boats have been invented and experimented with during recent years. The idea is an ancient one revived, as indeed are the large proportion of our boasted modern discoveries.

Aristotle describes a vessel of this kind (a diving-bell rather than a boat, however), used in the siege of Tyre more than two thousand years ago; and also refers to the divers being provided with an air-tube, “like the trunk of an elephant,” by means of which they drew a fresh supply of air from above the surface—a contrivance adopted in more than one of our modern submarines. Alexander the Great is said to have employed divers in warfare; Pliny speaks of an ingenious diving apparatus, and Bacon refers to air-tubes used by divers. We even find traces of weapons of offence being employed. Calluvius is credited with the invention of a submarine gun for projecting Greek fire.

The Bishop of Upsala in the sixteenth century gives a somewhat elaborate description of certain leather skiffs or boats used to scuttle ships by attacking them from beneath, two of which he claims to have personally examined. In 1629 we read that the Barbary corsairs fixed submarine torpedoes to the enemy’s keel by means of divers.

As early as 1579 an English gunner named William Bourne patented a submarine boat of his own invention fitted with leather joints, so contrived as to be made smaller or larger by the action of screws, ballasted with water, and having an air-pipe as mast. The Campbell-Ash submarine tried in 1885 was on much the same principle.

Cornelius van Drebbel, an ingenious Dutchman who settled in England before 1600, produced certain submersible vessels and obtained for them the patronage of two kings. He claims to have discovered a means of re-oxygenating the foul air and so enabling his craft to remain a long time below water; whether this was done by chemical treatment, compressed air, or by surface tubes no record remains. Drebbel’s success was such that he was allowed to experiment in the Thames, and James I. accompanied him on one of his sub-aquatic journeys. In 1626 Charles I. gave him an order to make “boates to go under water,” as well as “water mines, water petards,” &c., presumably for the campaign against France, but we do not hear of these weapons of destruction being actually used upon this occasion.

The “Holland” Submarine Boat.

These early craft seem to have been generally moved by oars working in air-tight leather sockets; but one constructed at Rotterdam about 1654 was furnished with a paddle-wheel.

Coming now nearer to our own times, we find that an American called Bushnell had a like inspiration in 1773, when he invented his famous “Turtles,” small, upright boats in which one man could sit, submerge himself by means of leather bottles with the mouths projecting outside, propel himself with a small set of oars and steer with an elementary rudder. An unsuccessful attempt was made to blow up the English fleet with one of these “Turtles” carrying a torpedo, but the current proved too strong, and the missile exploded at a harmless distance, the operator being finally rescued from an unpremeditated sea-trip! Bushnell was the author of the removable safety-keel now uniformly adopted.

Soon afterwards another New Englander took up the running, Fulton—one of the cleverest and least[Pg 145]
[Pg 146] appreciated engineers of the early years of the nineteenth century. His Nautilus, built in the French dockyards, was in many respects the pattern for our own modern submarines. The cigar-shaped copper hull, supported by iron ribs, was twenty-four feet four inches long, with a greatest diameter of seven feet. Propulsion came from a wheel, rotated by a hand winch, in the centre of the stern; forward was a small conning-tower, and the boat was steered by a rudder. There was a detachable keel below; and fitted into groves on the top were a collapsible mast and sail for use on the surface of the water. An anchor was also carried externally. In spite of the imperfect materials at his disposal Fulton had much success. At Brest he took a crew of three men twenty-five feet down, and on another day blew up an old hulk. In the Seine two men went down for twenty minutes and steered back to their starting-point under water. He also put in air at high pressure and remained submerged for hours. But France, England, and his own country in turn rejected his invention; and, completely discouraged, he bent his energies to designing boat engines instead.

In 1821 Captain Johnson, also an American, made a submersible vessel 100 feet long, designed to fetch Napoleon from St. Helena, travelling for the most part upon the surface. This expedition never came off.

Two later inventions, by Castera and Payerne, in 1827 and 1846 respectively, were intended for more peaceful objects. Being furnished with diving-chambers, the occupants could retrieve things from the bottom of the sea; Castera providing his boat with an air-tube to the surface.

Bauer, another inventor, lived for some years in England under the patronage of Prince Albert, who supplied him with funds for his experiments. With Brunel’s help he built a vessel which was indiscreetly modified by the naval authorities, and finally sank and drowned its crew. Going then to Russia he constructed sundry submarines for the navy; but was in the end thrown over, and, like Fulton, had to turn himself to other employment.

The fact is that up to this period the cry for a practical submarine to use in warfare had not yet arisen, or these inventions would have met with a far different reception. Within the last half century all has changed. America and France now rival each other in construction, while the other nations of Europe look on with intelligent interest, and in turn make their contributions towards solving the problem of under-wave propulsion.

America led the way during the Civil War blockades in 1864, when the Housatonic was sunk in Charleston harbour, and damage done to other ships. But these experimental torpedo-boats were clumsy contrivances compared with their modern successors, for they could only carry their destructive weapon at the end of a spar projecting from the bows—to be exploded upon contact with the obstacle, and probably involve the aggressor in a common ruin. So nothing more was done till the perfecting of the Whitehead torpedo (see Dirigible Torpedoes) gave the required impetus to fresh enterprise.

France, experimenting in the same direction, produced in 1889 Goubet’s submarine, patent of a private inventor, who has also been patronised by other navies. These are very small boats, the first, 16-1/2 feet long, carrying a crew of two or three men. Goubet No. 2, built in 1899, is 26-1/4 feet long, composed of several layers of gun-metal united by strong screw-bolts, and so able to resist very great pressure. They are egg-or spindle-shaped, supplied with compressed air, able to sink and rise by rearrangement of water-ballast. Reservoirs in the hull are gradually filled for submersion with water, which is easily expelled when it is desired to rise again. If this system goes wrong a false keel of thirty-six hundredweight can be detached and the boat springs up to the surface. The propulsive force is electricity, which works the driving-screw at the rear, and the automobile torpedo is discharged from its tube by compressed air.

“By the aid of an optical tube, which a pneumatic telescopic apparatus enables the operator to thrust above the surface and pull down in a moment, the captain of the Goubet can, when near the surface, see what is going on all round him. This telescope has a system of prisms and lenses which cause the image of the sea-surface to be deflected down to the eye of the observer below.

“Fresh air for the crew is provided by reservoirs of oxygen, and accumulations of foul air can be expelled by means of a small pump. Enough fresh air can be compressed into the reservoirs to last the crew for a week or more.”

The Gymnote, laid down in 1898, is more than double the size of the Goubet; it is cigar-shaped, 29 feet long by 6 feet diameter, with a displacement of thirty tons. The motive power is also electricity stored in accumulators for use during submersion, and the speed expected—but not realised—was to be ten knots.

Five years later this type was improved upon in the Gustave ZÉdÉ, the largest submarine ever yet designed. This boat, built of phosphor-bronze, with a single screw, measures 131 feet in length and has a displacement of 266 tons; she can contain a crew of nine officers and men, carries three torpedoes—though with one torpedo tube instead of two—has a lightly armoured conning-tower, and is said to give a surface speed of thirteen knots and to make eight knots when submerged. At a trial of her powers made in the presence of M. Lockroy, Minister of Marine, she affixed an unloaded torpedo to the battleship Magenta and got away unobserved. The whole performance of the boat on that occasion was declared to be most successful. But its cost proved excessive considering the small radius of action obtainable, and a smaller vessel of the same type, the Morse (118 × 9 feet), is now the official size for that particular class.

In 1896 a competition was held and won by the submersible Narval of M. Laubeuf, a craft shaped much like the ordinary torpedo-boat. On the surface or awash the Narval works by means of a BrulÉ engine burning oil fuel to heat its boilers; but when submerged for attack with funnel shut down is driven by electric accumulators. She displaces 100 odd tons and is provided with four Dzewiecki torpedo tubes. Her radius of action, steaming awash, is calculated at some 250 miles, or seventy miles when proceeding under water at five knots an hour. This is the parent of another class of boats designed for offensive tactics, while the Morse type is adapted chiefly for coast and harbour defence. The French navy includes altogether thirty submarine craft, though several of these are only projected at present, and none have yet been put to the practical tests of actual warfare—the torpedoes used in experimenting being, of course, blank.

Meanwhile in America experiments have also been proceeding since 1887, when Mr. Holland of New York produced the vessel that bears his name. This, considerably modified, has now been adopted as model by our Navy Department, which is building some half-dozen on very similar lines. Though it is not easy to get any definite particulars concerning French submarines Americans are less reticent, and we have graphic accounts of the Holland and her offspring from those who have visited her.

These vessels, though cigar-shaped liked most others, in some respects resemble the Narval, being intended for long runs on the surface, when they burn oil in a four-cylinder gasolene engine of 160 horse-power. Under water they are propelled by an electric waterproof motor of seventy horse-power, and proceed at a pace of seven knots per hour. There is a superstructure for deck, with a funnel for the engine and a small conning-tower protected by 4-inch armour. The armament carried comprises five 18-inch Whitehead torpedoes, 11 feet 8 inches long. One hundred and twenty tons is the displacement, including tank capacity for 850 gallons of gasolene; the full length is 63 feet 4 inches, with a beam of 11 feet 9 inches.

The original Holland boat is thus described by an adventurous correspondent who took a trip in her[3]: “The Holland is fifty-three feet long, and in its widest part it is 10-1/4 feet in diameter. It has a displacement of seventy-four tons, and what is called a reserve buoyancy of 2-1/2 tons which tends to make it come to the surface.

“The frames of the boat are exact circles of steel. They are set a little more than a foot apart. They diminish gradually in diameter from the centre of the boat to the bow and stern. On the top of the boat a flat superstructure is built to afford a walking platform, and under this are spaces for exhaust pipes and for the external outfit of the boat, such as ropes and a small anchor. The steel plates which cover the frame are from one-half to three-eighths of an inch in thickness.

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“From what may be called the centre of the boat a turret extends upwards through the superstructure for about eighteen inches. It is two feet in diameter, and is the only means of entrance to the boat. It is the place from which the boat is operated. At the stern is an ordinary three-bladed propeller and an ordinary rudder, and in addition there are two horizontal rudders—‘diving-rudders’ they are called—which look like the feet of a duck spread out behind as it swims along the water.

“From the bow two-thirds of the way to the stern there is a flooring, beneath which are the storage batteries, the tank for the gasolene, and the tanks which are filled with water for submerging; in the last one-third of the boat the flooring drops away, and the space is occupied by the propelling machinery.

“There are about a dozen openings in the boat, the chief being three Kingston valves, by means of which the submerging tanks are filled or emptied. Others admit water to pressure gauges, which regulate or show the depth of the vessel under water. There are twelve deadlights in the top and sides of the craft. To remain under water the boat must be kept in motion, unless an anchor is used.

“It can be steered to the surface by the diving rudders, or sent flying to the top through emptying the storage tanks. If it strikes bottom, or gets stuck in the mud, it can blow itself loose by means of its compressed air. It cannot be sunk unless pierced above the flooring. It has a speed capacity of from eight to ten knots either on the surface or under water.

“It can go 1500 miles on the surface without renewing its supply of gasolene. It can go fully forty knots under water without coming to the surface, and there is enough compressed air in the tanks to supply a crew with fresh air for thirty hours, if the air is not used for any other purpose, such as emptying the submerging tanks. It can dive to a depth of twenty feet in eight seconds.

“The interior is simply packed with machinery. As you climb down the turret you are confronted with it at once. There is a diminutive compass which must be avoided carefully by the feet. A pressure gauge is directly in front of the operator’s eye as he stands in position. There are speaking-tubes to various parts of the boat, and a signal-bell to the engine-room.

“As the operator’s hands hang by his sides, he touches a wheel on the port side, by turning which he steers the little vessel, and one on the starboard side, by turning which he controls the diving machinery. After the top is clamped down the operator can look out through plate-glass windows, about one inch wide and three inches long, which encircle the turret.

“So long as the boat is running on the surface these are valuable, giving a complete view of the surroundings if the water is smooth. After the boat goes beneath the surface, these windows are useless; it is impossible to see through the water. Steering must be done by compass; until recently considered an impossible task in a submarine boat. A tiny electric light in the turret shows the operator the direction in which he is going, and reveals the markings on the depth gauges. If the boat should pass under an object, such as a ship, a perceptible shadow would be noticed through the deadlights, but that is all. The ability to see fishes swimming about in the water is a pleasant fiction.

“The only clear space in the body of the boat is directly in front of the bench on which the man in the turret is standing. It is where the eighteen-inch torpedo-tube, and the eight and five-eighths inch aËrial gun are loaded.

“Along the sides of this open space are six compressed-air tanks, containing thirty cubic feet of air at a pressure of 2000 lbs. to a square inch. Near by is a smaller tank, containing three cubic feet of air at a fifty pounds pressure. A still smaller tank contains two cubic feet of air at a ten pounds pressure. These smaller tanks supply the compressed air which, with the smokeless powder, is used in discharging the projectiles from the boat.

“Directly behind the turret, up against the roof on the port side, is the little engine by which the vessel is steered; it is worked by compressed air. Fastened to the roof on the starboard side is the diving-engine, with discs that look as large as dinner-plates stood on end. These discs are diaphragms on which the water-pressure exerts an influence, counteracting certain springs which are set to keep the diving rudders at a given pitch, and thus insuring an immersion of an exact depth during a run.

“At one side is a cubic steel box—the air compressor; and directly in the centre of this part of the boat is a long pendulum, just as there is in the ordinary torpedo, which, by swinging backwards and forwards as the boat dives and rises, checks a tendency to go too far down, or to come up at too sharp an angle. On the floor are the levers which, when raised and moved in certain directions, fill or empty the submerging tanks. On every hand are valves and wheels and pipes in such apparent confusion as to turn a layman’s head.

“There are also pumps in the boat, a ventilating apparatus, and a sounding contrivance, by means of which the channel is picked out when running under water. This sounding contrivance consists of a heavy weight attached to a piano wire passing from a reel out through a stuffing-box in the bottom. There are also valves which release fresh air to the crew, although in ordinary runs of from one-half to one hour this is not necessary, the fresh air received from the various exhausts in the boat being sufficient to supply all necessities in that length of time.”

Another submersible of somewhat different design is the production of the Swedish inventor, Mr. Nordenfelt. This boat is 9-1/2 metres in length, and has a displacement of sixty tons. Like the Goubet it sinks only in a horizontal position, while the Holland plunges downward at a slight angle. On the surface a steam-engine of 100 horse-power propels it, and when the funnel is closed down and the vessel submerges itself, the screws are still driven by superheated steam from the large reservoir of water boiling at high pressure which maintains a constant supply, three circulation pumps keeping this in touch with the boiler. The plunge is accomplished by means of two protected screws, and when they cease to move the reserve buoyancy of the boat brings it back to the surface. It is steered by a rudder which a pendulum regulates. The most modern of these boats is of English manufacture, built at Barrow, and tried in Southampton Water.

The vessels hitherto described should be termed submersible rather than submarine, as they are designed to usually proceed on the surface, and submerge themselves only for action when in sight of the enemy.

American ingenuity has produced an absolutely unique craft to which the name submarine may with real appropriateness be applied, for, sinking in water 100 feet deep, it can remain below and run upon three wheels along the bottom of the sea. This is the Argonaut, invented by Mr. Simon Lake of Baltimore, and its main portion consists of a steel framework of cylindrical form which is surmounted by a flat, hollow steel deck. During submersion the deck is filled with water and thus saved from being crushed by outside pressure as well as helping to sink the craft.

When moving on the surface it has the appearance of an ordinary ship, with its two light masts, a small conning-tower on which is the steering-wheel, bowsprit, ventilators, a derrick, suction-pump, and two anchors. A gasolene engine of special design is used for both surface and submerged cruising under ordinary circumstances, but in time of war storage batteries are available. An electric dynamo supplies light to the whole interior, including a 4000 candle-power searchlight in the extreme bow which illuminates the pathway while under water.

On the boat being stopped and the order given to submerge, the crew first throw out sounding lines to make sure of the depth. They then close down external openings, and retreat into the boat through the conning-tower, within which the helmsman takes his stand, continuing to steer as easily as when outside. The valves which fill the deck and submersion tanks are opened, and the Argonaut drops gently to the floor of the ocean. The two apparent masts are in reality 3-inch iron pipes which rise thirty feet or more above the deck, and so long as no greater depth is attained, they supply the occupants with fresh air and let exhausted gases escape, but close automatically when the water reaches their top.

Once upon the bottom of the sea this versatile submarine begins its journey as a tricycle. It is furnished with a driving-wheel on either side, each of which is 6-1/2 feet in diameter and weighs 5000 lbs.; and is guided by a third wheel weighing 2000 lbs. journalled in the rudder. On a hard bottom or against a strong tide the wheels are most effective owing to their weight, but in passing through soft sand or mud the screw propeller pushes the boat along, the driving-wheels running “loose.” In this way she can travel through even waist-deep mud, the screw working more strongly than on the surface, because it has such a weight of water to help it, and she moves more easily uphill.

In construction the Argonaut is shaped something like a huge cigar, her strong steel frames, spaced twenty inches apart, being clad with steel plates 3/8-inch thick double riveted over them. Great strength is necessary to resist the pressure of superincumbent water, which at a depth of 100 feet amounts to 44 lbs. per square inch.

Originally she was built 36 feet long, but was subsequently lengthened by some 20 odd feet, and has 9 feet beam. She weighs fifty-seven tons when submerged. A false section of keel, 4000 lbs. in weight, can on emergency be instantly released from inside; and two downhaul weights, each of 1000 lbs., are used as an extra precaution for safety when sinking in deep water.

The interior is divided into various compartments, the living quarters consisting of the cabin, galley, operating chamber and engine-room. There are also a division containing stores and telephone, the intermediate, and the divers’ room. The “operating” room contains the levers, handwheels, and other mechanism by which the boat’s movements are governed. A water gauge shows her exact depth below the surface; a dial on either side indicates any inclination from the horizontal. Certain levers open the valves which admit water to the ballast-tanks in the hold; another releases the false keel; there is a cyclometer to register the wheel travelling, and other gauges mark the pressure of steam, speed of engines, &c.

A compass in the conning-tower enables the navigator to steer a true course whether above or below the surface. This conning-tower, only six feet high, rises above the centre of the living quarters, and is of steel with small windows in the upper part. Encircling it to about three-quarters of its height is a reservoir for gasolene, which feeds into a smaller tank within the boat for consumption. The compressed air is stored in two Mannesmann steel reservoirs which have been tested to a pressure of 4000 lbs. per square inch. This renews the air-supply for the crew when the Argonaut is long below, and also enables the diving operations to be carried on.

The maximum speed at which the Argonaut travels submerged is five knots an hour, and when she has arrived at her destination—say a sunken coal steamer—the working party pass into the “intermediate” chamber, whose air-tight doors are then closed. A current of compressed air is then turned on until the air is equal in pressure to that in the divers’ room. The doors of this close over india rubber to be air and water-tight; one communicates with the “intermediate,” the other is a trap which opens downwards into the sea. Through three windows in the prow those remaining in the room can watch operations outside within a radius varying according to the clearness of the water. The divers assume their suits, to the helmets of which a telephone is attached, so arranged that they are able to talk to each other as well as to those in the boat. They are also provided with electric lamps, and a brilliant flood of light streams upon them from the bows of the vessel. The derrick can be used with ease under water, and the powerful suction-pump will “retrieve” coal from a submerged vessel into a barge above at the rate of sixty tons per hour.

It will thus be seen how valuable a boat of this kind may be for salvage operations, as well as for surveying the bottom of harbours, river mouths, sea coasts, and so on. In war time it can lay or examine submarine mines for harbour defence, or, if employed offensively, can enter the enemy’s harbour with no chance of detection, and there destroy his mines or blow up his ships with perfect impunity.

To return the Argonaut to the surface it is only necessary to force compressed air into the space below the deck and the four tanks in the hold. Her buoyancy being thus gradually restored she rises slowly and steadily till she is again afloat upon the water, and steams for land.

We have now glanced briefly at some of the most interesting attempts—out of many dozens—to produce a practicable submarine vessel in bygone days; and have inquired more closely into the construction of several modern designs; among these the Holland has received especial attention, as that is the model adopted by our Admiralty, and our own new boats only differ in detail from their American prototype. But before quitting this subject it will be well to consider what is required from the navigating engineer, and how far present invention has supplied the demand.

The perfect submarine of fiction was introduced by Jules Verne, whose Nautilus remains a masterpiece of scientific imagination. This marvellous vessel ploughed the seas with equal power and safety, whether on the surface or deeply sunk beneath the waves, bearing the pressure of many atmospheres. It would rest upon the ocean floor while its inmates, clad in diving suits, issued forth to stroll amid aquatic forests and scale marine mountains. It gathered fabulous treasures from pearl beds and sunken galleons; and could ram and sink an offending ship a thousand times its size without dinting or loosening a plate on its own hull. No weather deflected its compass, no movement disturbed its equilibrium. Its crew followed peacefully and cheerfully in their spacious cabins a daily round of duties which electric power and automatic gear reduced to a minimum. Save for the misadventure of a shortened air-supply when exploring the Polar pack, and the clash of human passions, Captain Nemo’s guests would have voyaged in a floating paradise.

Compare with this entrancing creation the most practical vessels of actual experiment. They are small, blind craft, groping their way perilously when below the surface, the steel and electrical machinery sadly interfering with any trustworthy working of their compass, and the best form of periscope hitherto introduced forming a very imperfect substitute for ordinary vision.

Their speed, never very fast upon the surface, is reduced by submersion to that of the oldest and slowest gunboats. Their radius of action is also circumscribed—that is, they cannot carry supplies sufficient to go a long distance, deal with a hostile fleet, and then return to headquarters without replenishment.

Furthermore, there arise the nice questions of buoyancy combined with stability when afloat, of sinking quickly out of sight, and of keeping a correct balance under water. The equilibrium of such small vessels navigating between the surface and the bottom is extremely sensitive; even the movements to and fro of the crew are enough to imperil them. To meet this difficulty the big water-ballast tanks, engines and accumulators are necessarily arranged at the bottom of the hull, and a pendulum working a helm automatically is introduced to keep it longitudinally stable.

To sink the boat, which is done by changing the angle of the propeller in the Goubet and some others, and by means of horizontal rudders and vanes in the Nordenfelt and Holland, it must first be most accurately balanced, bow and stern exactly in trim. Then the boat must be put into precise equilibrium with the water—i.e. must weigh just the amount of water displaced. For this its specific gravity must be nearly the same as that of the water (whether salt or fresh), and a small accident might upset all calculations. Collision, even with a large fish, could destroy the steering-gear, and a dent in the side would also tend to plunge it at once to destruction.

Did it escape these dangers and succeed in steering an accurate course to its goal, we have up to now little practical proof that the mere act of discharging its torpedo—though the weight of the missile is intended to be automatically replaced immediately it drops from the tube—may not suffice to send the vessel either to bottom or top of the sea. In the latter case it would be within the danger zone of its alarmed enemy and at his mercy, its slow speed (even if uninjured) leaving it little chance of successful flight.

But whatever the final result, one thing is certain, that—untried as it is—the possible contingency of a submarine attack is likely to shake the morale of an aggressive fleet.

“When the first submarine torpedo-boat goes into action,” says Mr. Holland, “she will bring us face to face with the most perplexing problem ever met in warfare. She will present the unique spectacle, when used in attack, of a weapon against which there is no defence.... You can send nothing against the submarine boat, not even itself.... You cannot see under water, hence you cannot fight under water. Hence you cannot defend yourself against an attack under water except by running away.”

This inventor is, however, an enthusiast about the future awaiting the submarine as a social factor. His boat has been tested by long voyages on and below water with complete success. The Argonaut also upon one occasion travelled a thousand miles with five persons, and proved herself “habitable, seaworthy, and under perfect control.”

Mr. Holland confidently anticipates in the near future a Channel service of submerged boats run by automatic steering-gear upon cables stretched from coast to coast, and eloquently sums up its advantages.

The passage would be always practicable, for ordinary interruptions such as fog and storms cannot affect the sea depths.

An even temperature would prevail summer and winter, the well-warmed and lighted boats being also free from smoke and spray.

No nauseating smells would proceed from the evenly-working electric engines. No motion cause sea-sickness, no collision be apprehended—as each line would run on its own cable, and at its own specified depth, a telephone keeping it in communication with shore.

In like manner a service might be plied over lake bottoms, or across the bed of wide rivers whose surface is bound in ice. Such is the submarine boat as hitherto conceived for peace or war—a daring project for the coming generation to justify.