“No type of boat in the navy has received such crucial tests as the _Holland_. The submarine boat to-day is further advanced in its development than any type of naval vessels that I am aware of. I desire to say that in my opinion the _Holland_, without any improvements, is to-day the greatest vessel for harbour and coast defence ever known.”—Mr. LEWIS NIXON, builder of the _Holland_. When the British Admiralty decided to experiment with submarine boats, the type chosen was that invented by Mr. John P. Holland. It is therefore fitting that some account should be given of the various stages through which the Holland boat has gone in the course of its evolution. Although Mr. John P. Holland, of Paterson, New Jersey, U.S.A., made a number of experiments in the sixties, his first real submarine boat was not built until 1875. _Holland No. 1_ may be described as an under-water canoe, for there was only room for one occupant, who propelled the vessel along by means of pedal-acting mechanism, a small screw being fitted at the stern. The dimensions were:— Length 16 feet Beam 20 inches Depth 2 feet [Illustration: MR. HOLLAND’S EARLIEST SUBMARINE. (1875.) ] It was divided into three parts; the two end ones were used as air reservoirs and submersion tanks, and that in the centre contained the operator, whose head was encased in a diver’s helmet. The vessel was driven by a small propeller projecting from the stern joist, and beneath this was the rudder. _Holland No. 2_ was constructed in 1877 at the Albany City Iron Works of New York. Its dimensions were:— Length 10 feet Beam 3·5 feet Depth 3 feet It had a double shell, and in the space between water ballast could be admitted for submersion. The motor was a petroleum engine of 4 h.p., working a screw at the stern. Two rudders, one vertical, the other horizontal, were carried, and experiments showed that the latter acted better when placed at the stern than when on the side. After a series of trials on the Passaic River, Mr. Holland removed the machinery and sank his boat under Falls Bridge at Patterson, where it probably remains at this day. _Holland No. 3_ was commenced in 1879 in the yards of the Delamater Iron Company of New York City, and finished in 1881. Its dimensions were:— Length 31 feet Beam 6 feet Depth 6 feet Displacement 19 tons