288 SUBMARINE NAVIGATION. 



The underwater speed is knots and the radius of action when sub- 

 merged about 00 miles. No oflicial particuhirs have been published 

 as to the contract price for these vessels, which is certainly an unde- 

 sirable course to adopt, seeing that for other and admittedly sufiicient 

 reasons these contracts have not been subject to coinpetition as yet. 

 It may be hoped that the Admiralty will reconsider this matter and 

 treat submarines similarly to other vessels. 



In French official classification a distinction is made between sub- 

 mariries and submersibles, and this terminology has been the cause 

 of some confusion. Both classes are capable of diving when required 

 and both can make passages at the surface. In this surface condition 

 a considerable portion of the vessel lies above the water surface and 

 constitutes what is technically called a " reserve of buoyancy." In 

 the submersible this reserve of buoyancy and the accompanying free- 

 board is greater than in the submarine type, and in this respect lies 

 the chief difference between the two types. The submersible has 

 higher freeboard and greater reserve of buoyancy, which secures 

 better seagoing qualities and greater habitability. The deck or 

 platform is situated higher above water, and to it the crew can find 

 :iccess in ordinary Aveather when making passages and obtain exer- 

 cise and fresh air. Recent exhaustive trials in France are reported 

 to have established the great superiority of the submersible type 

 when the service contemplated may involve sea passages of consider- 

 able length. The French policy, as recently announced, contemplates 

 the construction of submersibles of about 400 tons (lis])lacement for 

 such extended services and proposes to restrict the use of submarines 

 to coast and harbor defense, for which vessels of about 100 tons dis- 

 placement are to be emi)loved. All recent British submarines would 

 be ranked as submersil:)les according to the French classification, and 

 it is satisfactory to know, as the result of French experiments, 

 that our policy of construction proves to have distinct advantages. 

 In addition to these two types of diving or submarine vessels, the 

 French are once more discussing plans which have been repeatedly 

 ])ut forward and practically applied by M. Goubet, namely, the 

 construction of small portable submarine vessels which could be 

 lifted on board large ships and transported to any desired scene of 

 operations. In the royal navy for many years past it has been the 

 practice to similarly lift and carry second-class torpedo or vedette 

 boats about 20 tons in weight. Lifting appliances for dealing 

 with these heavy boats have been designed and fitted in all our large 

 cruisers and in battle ships, and a few ships have been built as '' boat 

 carriers." The first of these special depot ships in the royal navy 

 was the Vvlca7i, ordered in 1887-88, the design being in essentials that 

 prepared by the writer at Elswick in 1883. The French have also 

 built a special vessel, named the Foud7'e, which has been adapted for 



