The development of the sea-going submarine will bring with it, doubtless, many improvements in the vessels which have been first mentioned, viz., vessels for the defence of ports and their approaches. It is not possible yet to say to what extent the “Holland” boats building at Barrow will prove fairly satisfactory, although my acquaintance with this class of vessel for several years past has given me a favourable impression of it—favourable, that is, as furnishing many elements of initial success. More than this could not be reasonably expected; nor can we doubt that with the skill of both the Admiralty designers and those of the great manufacturing establishment which has produced the first few vessels concentrated upon this class of boat, immense improvements may be confidently anticipated. Of the third class of vessels before referred to the Goubet boat may be regarded as a commencing type. The principle of this boat appears to be that of carrying and launching torpedoes from external supports, the size and buoyancy of the vessels being very small by comparison with those of vessels which carry their torpedoes inside. M. Goubet appears to go beyond this principle, and to have other ideas, which are mentioned in the text of this work. Suffice it here to say that the idea of relieving the submarine boat from the necessity of carrying its torpedoes with it, goes a long way towards furthering the use of submarine torpedo craft carried on the decks, or at the davits of battleships and cruisers.