THE SUBMARINE OF TO-DAY AND TO-MORROW. 211 



the battle fleet. Should this second theory be adopted, it appears certain that there 

 would arise an imperative demand for much higher surface speeds, which, of 

 course, would involve marked increase in the displacement and cost of each unit. At 

 the present writing, the largest defense boats ordered by the United States are of 

 about 500 tons surface displacement, with a speed of 14 knots. If the policy under 

 discussion were to be adopted, it would perhaps be logical to pass at once to materi- 

 ally higher displacements and speeds, say Soo tons and 17 to 18 knots. Following 

 the natural law of naval evolution which seems to look toward the attainment of the 

 maximum power in each unit, we would expect to see this displacement and speed in- 

 crease from year to year. Carried to the extreme and logical end, this policy would 

 eventually result in a merging of the defensive type into the offensive type. When 

 that point is reached, if ever, our present units would probably be assigned to local 

 defense and their numbers would be supplemented by new constructions of moderate 

 displacement. 



Having in view the strong differences of opinion on the subject which now exist 

 in the Navy, the author does not anticipate the definite adoption at an early date 

 of either method to the exclusion of the other. In fact, if the past is a safe guide, 

 we may expect our Navy Department to keep "in the middle of the road," thus avoid- 

 ing all sudden radical changes. It follows then that we may reasonably expect a com- 

 promise in the form of the construction of boats, which, while larger than necessary 

 or desirable for local defense purposes, can still perform that duty, and at the same 

 time possess the necessary habitability and the "effective" radius to enable them to 

 keep the sea for long periods of time and to operate at a long distance from their 

 base. Such a type would thus also be available for use according to the second 

 method and on the whole should be very efficient for such purposes, since, on account 

 of the moderate displacement involved, it will be practicable to compensate for lack 

 of high surface speed by an increase in numbers. In fact, if an increase in numbers 

 be coupled with adequate scouting service, the final efficiency obtained from a given 

 expenditure may be greater if the speed of the flotillas is moderate than if it be high. 



As noted above, the necessity for sea-keeping qualities will in itself place some 

 lower limit on the surface displacement. Actual experience, which is really the only 

 safe guide, appears to fix this limit at about 350 tons. In this connection, it may be 

 interesting to note some of the most notable achievements of submarines in the mat- 

 ter of long voyages in the open sea. Some years ago, the U. S. S. Salmon, now the 

 D-3, of 288 tons surface displacement, made a successful trip from Boston to Ber- 

 muda and return, the journey involving a stretch of about 700 miles from port to 

 port. This year, a large number of submarines of 350 tons displacement have suc- 

 cessfully crossed the Atlantic under their own power from Canadian waters, which 

 performance, taking the number of boats and the length of the voyage into account, 

 appears now to be a record. In the French Navy, the Faraday of 400 tons sur- 

 face displacement has successfully made the passage from Rochefort to Toulon, a 

 stretch of 1,730 miles. The voyages of the British "E" class from England to Aus- 

 tralia, to the Dardanelles and to Russian Baltic waters, as well as the voyages of the 



