The Russian Government is said to favour submarines of the Lake pattern, so named after its American inventor, of which a great deal is thought; and America is said to have adopted both Holland and Lake submarines. One Lake boat was provided with wheels, and went on a submarine motor tour along the New England coasts, and Mr. Lake finally offered to demonstrate the usefulness of his vessel by finding and cutting the cables of the mines protecting one of the American ports. This was more than the American Government could allow, so he had a cable laid across a harbour mouth, and having found it, severed it. The Italian authorities have modified the Holland and French plans to suit their own ideas, and though their boats are said to have given excellent results, singularly little is known about them. All makes of submarines and submersibles have to return to the surface at fairly frequent intervals to renew the supply of fresh air, and have to approach it at even more frequent intervals in order that the navigating officer may see what are his surroundings at the surface, and, in time of war, whether it would be safe for him to bring his vessel up. The difficulty of finding his way about without revealing his whereabouts by exposing the periscope to view is one of the greatest the commander of a submarine has to meet, but it would be futile to say that the ingenuity of scientific inventors will not overcome even this difficulty. TORPEDO BOATS AND DESTROYERS When the _Iris_ was given a speed of 18½ knots, many declared that the limit in speed, with a due regard to safety, had been attained. Much the same was said when Mr. Thornycroft brought out the _Lightning_ in 1876, the first real torpedo boat ever built for the British Navy, which had a speed of 18½ knots. Now, however, the speed has been more than doubled, and the sea-going qualities of the vessels are so much better that there is scarcely room for comparison. In 1873 the same firm built for the Norwegian Government a small steamboat intended to be employed in torpedo work only. The _Lightning_ was 87 feet over all, with a displacement on her trials of 28½ tons; now torpedo boats are a hundred feet or so longer. [Illustration: THE EARLIEST EUROPEAN TORPEDO BOAT. BUILT FOR THE NORWEGIAN GOVERNMENT IN 1873. SPEED 18 KNOTS. _Photograph supplied by Messrs. J. Thornycroft & Co., Ltd._] [Illustration: FIRST BRITISH TORPEDO BOAT, “LIGHTNING.” SPEED 18 KNOTS. BUILT IN 1876. _Photograph supplied by Messrs. J. Thornycroft & Co., Ltd._] [Illustration: H.M. TORPEDO BOAT NO. 79, BUILT IN 1886. _Photograph by Stephen Cribb, Southsea._] [Illustration: H.M.S. “VULCAN.” _Photograph by E. Sankey, Barrow._]