On the surface the motor is a gasoline engine of the Otto type of 50 h.p., giving a speed of about 7 knots an hour, and under water an electric motor, capable of giving 50 h.p. for 6 hours or 150 h.p. for 2 hours, is used. The battery of accumulators consists of 66 cells, giving 350 amperes for 4 hours, and allowing a speed of 8 knots an hour. The radius of action on the surface is 1,500 miles at 7 knots without a renewal of gasoline, and it can go 50 knots under water without coming to the surface. In order to dive water ballast is admitted until the boat is flush with the water, and it is then steered down an incline by her two horizontal rudders at the stern, carried in addition to the ordinary vertical rudder. It has a reserve buoyancy which tends to bring it to the surface in case of accident. It can dive to a depth of 28 feet in 8 seconds. The armament was intended originally to consist of three tubes—two at the bows and one at the stern; two were to throw aerial torpedoes and shells, while the third was to discharge Whitehead torpedoes. The submarine gun aft, which was worked by pneumatic power, and was capable of throwing 80 lbs. of dynamite a distance of about half a mile, was, however, abandoned. The aerial gun at the bows is 11·25 ft. long and 8 in. in diameter, and each of the projectiles weighs 222 lbs., and carries 100 lbs. of gun-cotton. This gun can shoot these projectiles a distance of one mile. The torpedo tube is 18 in., and three torpedoes are carried; they have a running capacity of more than half a mile at a speed of 30 knots. On the top of the boat a flat superstructure is built to afford a walking platform, and underneath this are spaces for exhaust pipes, and for the external outfit of the boat, such as ropes and a small anchor. From the centre of the boat a turret extends upward through the superstructure about 18 inches. It is about 2 feet in diameter, and is the only means of entrance to the boat; it is also the place from which the boat is operated. As Mr. Holland had been experimenting with submarine craft for 25 years, and as he now considered that he had secured a practical result, and that his newest boat would do all that he claimed, he requested the United States Admiralty to make a series of exhaustive trials with the _Holland_. These trials accordingly took place, and having been found to be satisfactory, the _Holland_ was purchased by the U.S. Government on April 11, 1900. The price paid was $150,000, and the Company stated that the vessel had cost them, exclusive of any office expenses, or salaries of officers, $236,615,427. The _Holland_ was formally placed in commission under the command of Lieut. Harry H. Caldwell, U.S.N., on October 13, 1900, but the boat had been under the charge of this officer since June 25, 1900. An Act making appropriations for the Naval Service for the fiscal year ending June 30, 1901, which was approved on June 7, 1900, contained the following item:—