TO THE NEEDS OF THE UNITED STATES NAVY. 113 
Thus, as a matter of logistic economy, the submarine employed on this service re- 
quired a large radius of action which entailed a considerable size—about 800 tons. 
Our attention has been particularly centered on these large craft because their deeds 
attracted most notice, but they are not the only ones employed. We have every reason 
to believe that, where submarines are needed for their proper defensive role to protect 
the German coasts, much smaller ones are used. Similarly, the English, who have 
the mastery of the sea, yet need submarines to aid in the protection of their ports 
against sudden raids, make use of small ones. We know this because they have 
bought such boats in the United States, and a number of them held at Boston for 
delivery after the war are now to be seen there. 
So far as we know, submarines have accomplished little or nothing during the 
current war when acting in company with the main fleets. At the battle of Jutland 
last May they seem to have been absent or ineffective. 
The evidence of the present war as to submarines may be summarized by saying 
that on both sides they have obtained a degree of success in defense, to the extent 
of forbidding the approach of the main fleets of both sides to hostile coasts. In this 
successful coast defense, submarines have been greatly aided by mines. 
The use of submarines for the purpose of strategic attack has been less success- 
ful, although Germany’s attack, in particular, has arrested much attention. The 
submarine strategic attack has been chiefly directed against commerce, by the Brit- 
ish and Russians in the Baltic Sea against German trade with Sweden, and by the 
Germans at the entrance to the English Channel against the ocean trade of France 
and Great Britain. While this destruction of commerce has been serious, it has not 
led to conclusive results, although the narrow waters in which this contest has 
taken place have been favorable to the efforts of submarines because commerce has 
been obliged to cross the areas infested by them. 
In estimating the value of submarines in the current war we must not attribute 
the present shortage of commercial shipping wholly to the deeds of submarines. 
In the order of their importance the factors in this shortage seem to be :—First, the 
great military and naval demands made upon commercial shipping; second, the in- 
ternment at home or abroad of all or nearly all shipping of the central powers; third, 
the delays imposed upon allied shipping by the patrol and mine-sweeping services 
which have adopted a retardatory but necessary administrative system for the pro- 
tection of ships passing through dangerous areas; fourth, the actual loss of ship- 
ping caused by submarines which seems to have been about 3 per cent a year, more 
or less, nearly the same the English merchant service encountered without serious 
consequences in the Napoleonic wars. 
The foregoing discussion has had the objective of placing us in a position to 
consider what type of submarine will best suit the requirements of our own navy, 
and this we shall now proceed to do. 
The geographic situation of the United States, with a very extended coast-line, 
much of which is remote from possible enemies and borders great oceans, is very 
different from that of the present combatants, who are separated by comparatively 
