SUBMARINE NAVIGATION. 243 



use officers and men of the royal navy will be as expert as any of 

 their rivals. Bnt when all that is possible has been done, it mnst 

 remain true that increase in offensive power and in innnunity from 

 attack obtained by submergence will be acconi})anied by unavoidable 

 limitations as well as by special risks resulting from the sacrifice of 

 buoyancy and the great reduction in longitudinal stability wdiich are 

 unavoidable when diving. These considerations have led many per- 

 sons to favor the construction of so-called surface boats rather than 

 submarines. They would resemble submersibles in many resjjects, 

 but the power of diving would be surrendered, although they would 

 be so constructed that by admitting water by special tanks they 

 could be deeply immersed and show only a small target above the 

 surface when making an attack. There would be no necessity in 

 such surface vessels to use electric motors and storage batteries, since 

 internal combustion engines could be used under all circumstances. 

 Hence it would be possible without increase of size to construct 

 vessels of greater speed and radius of action and to simplify designs 

 in other important features. It is not possible to jDredict whether 

 this suggestion to adopt surface boats rather than submersibles will 

 have a practical result, but it is unquestionable that improvements 

 in or alternatives to internal combustion engines will favor the in- 

 crease of power in relation to weight, and so will tend to the pro- 

 duction of vessels of higher speed. The comparatively slow speed of 

 existing submarines as compared Avith destroyers and torpedo boats 

 of ordinary types admittedly involves serious limitations in their 

 chances of successful attack on vessels under way, and higher surface 

 speeds are desirable. 



Concurrently with the construction of submarines, experiments 

 have been made in this country and abroad to discover the best means 

 of defense against this method of attack. Here, again, authentic 

 details are necessarily wanting, since the various naval authorities 

 naturally wish to keep discoveries to themselves. It is very probable, 

 however, that published accounts of tests between swift destroyers, 

 vedette boats, and submarines are not altogether inaccurate, and 

 according to these accounts the periscopes of submarines have been 

 found useful by assailants as the means of determining the position 

 of the submarines and aiding their entanglement. Comparatively 

 limited structural damage to a submarine in the diving condition may 

 be accomj^anied by an inflow of water in a short period which wdl 

 result in the loss of the vessel. The accident to Submarine A 1, which 

 was struck by a passing mail steamer, illustrates this danger. It is 

 reasonable to accept the published reports that large charges of high 

 explosives exploded at a moderate distance may have a serious effect 

 against submarines and cause them to founder. Their small reserve 

 of buoyancy in the diving condition makes them specially liable to 



