a wearisome test, and survive many a baseless doubt, before it acquires a right of way.

One objection to Ericsson's heavy guns was the alleged impossibility of handling them aboard ship. Their designer once more came to the rescue. His wrought-iron gun-carriage, with its friction gear, checked the recoil of a 12-inch gun with a 30-pound charge in a distance of 16 inches. Yet more: on the Spanish gunboat Tornado, he provided a rotary gun-carriage and transit platform for heavy guns, enabling a gunner to aim at any point of the compass. Here he repeated in effect the mechanism of his revolving turret, with its sweep through a full circle.

From guns Ericsson now passed to torpedoes. He held that when stationary they had little or no value; his experiments led him to expect much from torpedoes properly directed and propelled. In 1870, he devised a torpedo driven and steered by compressed air carried through a flexible tube, paid out from a reel either on board the weapon or on shore. At intervals for five years Ericsson continued his experiments. In the spring of 1875, Commodore W. N. Jeffers, Chief of the Naval Bureau of Ordnance, reported that a model torpedo which he had received from Ericsson "worked regularly without the slightest trouble. . . . I have exhibited it to other chiefs of Bureaus, and to other naval officers, who were free in their expressions of wonder and satisfaction at the successful manner in which it operated."

Commodore Jeffers now placed at the disposal of Ericsson a smooth-bore 15-inch gun with its carriage, mounted on a Navy Yard scow. With this gun tests were conducted at Sandy Hook, proving that an elongated 15-inch shell forming a torpedo projectile 10 feet in length, designed to carry dynamite or other high explosive, could be fired in any direction from an ordinary smooth-bore gun, using a small charge of powder as the impelling agent. The plan

embraced a revolving turret for projecting and directing the gun. This turret Ericsson regarded as indispensable, and when Commodore Jeffers wished it to be omitted, the experiments were discontinued. Ericsson, on his own initiative, now proceeded to plan his famous Destroyer, which embodied his matured ideas of torpedo warfare.

The Destroyer was a comparatively small, swift, armorclad vessel, with a submarine gun to project torpedoes. All her vital parts were deeply submerged, and it was in

INFLATED AIR BAGS

LONGITUDINAL SECTION OF "DESTROYER" SHOWING GUN AND

PROJECTILE

[From "Life of John Ericsson" by W. Conant Church. Copyright, by Charles Scribner's Sons, New York, 1891.]

tended that her pace should equal or excel that of the craft she sought to destroy. Ericsson submitted his plans to the Navy Department; three years passed, and nothing was done. He decided to look elsewhere than to Washington. His experiments were so gratifying that on August 7, 1880, he announced to his friends, the Delamater Company, who built the Destroyer: "Ironsides are doomed. Our torpedo, with the propelling piston bolted to its aft end, went yesterday 275 feet in a direct course under water, and then floated to the surface. The torpedo was not fully loaded, hence did not go as far as it might. Enough was accomplished, however, to show that we can sink an enemy with

out ram, steam-launch or spar-torpedo of our navy. All these devices are gone to the dogs."

Commander Jeffers was relieved from his office on July 1, 1881. His successor did not regard the Destroyer with favor. He held that the projectile of the submarine gun should have more range, ignoring the fact that the range of a missile fired in so dense a medium as water is very limited. Aside from this, a longer range would demand a greater velocity, demanding a charge so heavy as to shatter a projectile of the necessary lightness. The plans were now submitted to a naval board, with Admiral Selfridge as its chairman. They reported favorably, and received the concurrence of Admiral Porter, the head of the Navy, who sought from Congress an appropriation for the purchase of the Destroyer, urging Ericsson to keep her construction a secret from foreigners. Admiral Porter in formal terms recommended that twenty steel vessels be built on Ericsson's plans, with quadruple expansion engines to assure a speed of thirty miles an hour. To this proposal the new chief of the Ordnance Bureau demurred, insisting on conditions to which Ericsson would not agree. These conditions included a thorough test of the Destroyer at its inventor's cost, and at sea, although the vessel was not built for sea service. And, further: it was required that her guns employ high explosives. In vain Ericsson pleaded that these terms would subject him, in case of accident, to the penalties of manslaughter, or, at least, to heavy damages, as his ship did not hold a Government commission. He justly said that it was unfair to ask him to add twenty thousand dollars to the hundred thousand he had already expended in solving a problem of national defense.

One-half the cost of the Destroyer had been advanced by Mr. C. H. Delamater, and he grew weary of the long delays in canvassing for its adoption. His interest in Ericsson prompted him to protest against his devoting to a thank

less public service any more of the life of an octogenarian. To the end of his days Ericsson was warmly concerned in the Destroyer, though he had little hope of aid from a nation which in forty years had not found time to pay him for his work on the Princeton. Twice he offered to build for the Navy Department an improved Destroyer, with a guarantee of success, relieving the Department of all responsibility. His offers were declined. In 1886, in his eighty-fourth year, he wrote to the Hon. A. H. Cragin :

"The success of the Destroyer would destroy the prospects of the powerful fortification and gun interest, which looks forward to an expenditure of one hundred millions within a few years. Then we are opposed by the ironclad shipbuilding and armorplate combinations; not to mention torpedo-boat builders, submarine-boat projectors, and dynamite gun manufacturers, all against us, as their plans will be worthless if foreign ironclads can be shattered and our harbors defended without guns and fortifications, by the employment of the simple and cheap submarine artillery system."

The cost of the British Inflexible, with its turret and armament, was $3,250,000. For this sum a fleet of thirty Destroyers could be built, and one-half of the three hundred and fifty men forming the crew of the Inflexible could man them all. To the four heavy guns of the larger vessel they would oppose thirty submarine cannon, each having the huge bulk of the armorclad as a target for its 500 pounds of high explosive. Was it not better, Ericsson argued, to distribute the risks of war among thirty vessels than to center them in a single huge craft? And could there be any doubt that the advantage would rest with the navy which chose the superior weight of metal,— or, in this case, of explosive?

On April 27, 1887, Ericsson wrote to the Secretary of the Navy, the Hon. William C. Whitney, stating that he

had just completed the plan of a vessel for harbor defense: she was of the Destroyer type, 24 feet beam, 13 feet deep, and carried a projecting belt of steel armor 3 inches thick and 30 inches deep, extending around to her outer hull. This armor, backed by oak planking, 31⁄2 inches thick, was sufficient protection against the fire of machine guns, and the vessel, when trimmed for conflict, would be nearly submerged. The portion of the cabin, projecting 31⁄2 feet above the main deck, was similarly protected. The breast armor for protection against heavy guns in fighting, bow on, was of inclined compound steel plates 30 inches thick, backed by 6 feet of oak timber. Ericsson asked $275,000 as the price of this vessel. His offer to build it was not accepted.

66

In 1876, Ericsson justly described himself to an intimate friend, as the man who has done more to promote marine engineering, mechanical motors, and implements of naval warfare than any other ten persons together during the last thirty years." Let us review his improvements in the steam engine, which, as a prime-mover, he vainly endeavored to supersede. His steam engines, from those built for the little tug Stockton, in 1839, to those of 4,500 horsepower for the Dictator in 1882, all had one feature in common, original with him. They brought the power of two engines to bear at right angles upon one crank-pin. In another invention he gave effect to a suggestion of James Watt, by making a piston vibrate within a semi-cylinder. Ericsson introduced this design in the Princeton, and applied it with modification in the Edith and the Massachusetts. In 1859, the United States Navy sought an engine specially adapted to screw propulsion. Ericsson responded with a semi-cylinder of qualified type. He divided a cylinder midway by a steam-tight partition, forming two short cylinders, each with a piston: the two pistons moved in opposite directions, and were attached to the same crank on the pro