_It may be said that the encouragement given to the inventor by the Admiralty is so scanty as to make him shy of offering them his ideas. Let us hope, now that Lord Selborne and Mr. Arnold Forster are at the Admiralty, that the bad old days when inventors were snubbed, and novel ideas ridiculed, have gone never to return. The submersible craft of to-day is no longer an ingenious toy; it is a practiced engine of warfare of no mean value. But there is vast room for improvement in its design. It must be endowed with more speed, its longitudinal stability must be improved, and its appliances for under-water vision perfected. Are there not Britons willing to devote their energies to the realisation of the ideal submarine?_ _The author has derived his information from a great many sources, some of which are mentioned in the brief Bibliography at the end of the book._ _He desires to express his thanks to Messrs. Vickers Sons & Maxim, the Holland Torpedo-boat Company, Mr. P. W. D’Alton, Lieutenant A. T. Dawson, late R.N., Mr. Simon Lake and others, for information kindly given him respecting various boats and for photographs. To Mr. Alan H. Burgoyne his thanks are due for permission to use some of his original sketches._ ROYAL SOCIETIES’ CLUB, ST. JAMES STREET, S.W. INTRODUCTION BY ADMIRAL THE HON. SIR E. R. FREMANTLE, G.C.B, C.M.G. (_Rear-Admiral of the United Kingdom._) The natural attitude of the Naval mind towards submarines is the same now as that expressed by Lord St. Vincent when Fulton invented the notorious “catamaran” expedition. Fulton had been trying some experiments before Pitt, who favoured the project, to which Lord St. Vincent, then First Lord of the Admiralty, was strongly opposed, and he bluntly stated that “Pitt was the greatest fool that ever existed to encourage a mode of war which those who commanded the seas did not want, and which, if successful, would deprive them of it.” It was, our Admiralty recently held, “the weapon of the weaker power, and not our concern,” then we were to “watch and wait,” which sounded plausible but was evidently dangerous, and as the success of the French submarines became too evident we were forced to follow suit. As Lord Selborne reminded us when speaking about the boilers, we have too often ignored new inventions and resisted change till we were left well behind in the race, as we were with ironclads, breech-loading guns, and other improvements in naval warfare.