Go Slow on Crimea
Why Ukraine Should Not Rush to Retake the Peninsula
JAPAN went to war because she believed that her air power was dominant in the Far East and that her air coverage of the seized territories could be made secure. Failure to appreciate the primary role assigned to air power in Japanese plans has been the source of much western confusion about the campaign in the Pacific, and could be a serious danger to the peace.
For many years it has been popularly assumed in the west that a war in the Far East would be decided by a great naval battle between Japanese and western fleets, and that in that battle the Japanese fleet faced certain destruction. More careful students of Pacific strategy concluded as far back as 1922, the time of the first naval limitations treaties, that the Japanese Navy would remain close to its base and would risk a major naval engagement only after the enemy fleet had been cut down by submarine attacks and weakened by having to fight far from its own bases. Later it became apparent that the Imperial Japanese Navy would probably engage the enemy fleet only if it were assured of the support of land-based aircraft. But not until the war was actually in progress did it become plain that Japan had assigned her Navy third place among the branches of her armed services. The expanded empire which Japan coveted was to be seized by the forces of all arms, with the Army and the Air Force taking the leading parts. It was to be defended from counterattack principally by air power.
Before the war began, westerners complacently believed that the Japanese were incapable of using air power effectively. Actually, the Japanese militarists had for many years planned to employ it as their chief weapon. To conceal their strategy, they took great pains in the years between the wars to publicize their supposed reliance upon their Navy. Devotion to sea power was used as a mask to cover aerial planning and preparations.
The future course of the war against Japan cannot be properly understood except against this background of Japanese reliance upon air power. Japan's selection and employment of air power as her prime weapon was strategically sound. Air power is peculiarly applicable to the geographic conditions of the Pacific and the Far East. Though the Japanese strategy has failed, due especially to the ability of American airmen to destroy Japanese aircraft in ratios much greater than the two-to-one losses which Japan might have taken and survived, the problems which our forces will face as they press into Japan's home waters will be even greater than those they have already overcome. Americans at home are still inclined to underestimate the degree to which Japan is airminded. We shall do well to expect that in coming months the Japanese will be able to employ masses of planes operating from adequate airfields such as they have lacked in other regions of the Pacific.
And since we wish no further surprises in the Far East after this war is over, we must never forget that as air power grows in strength and range it will become an even more appropriate weapon for aggressive warfare in this area. The merits of the Japanese plan to dominate the Far East by means of air power, and the shrewdness with which the plan was developed, warn us that it will be many years before we can afford to relax our guard. Indeed, if the "liberation" of Japan brings an end to regimentation and introduces better health services, that may result in turn in the correction of the very defects most noticeable in Japanese fliers -- lack of individual initiative and deficiencies of sight and hearing caused by poor diet. It was probably the existence of those defects which in large measure enabled our airmen to nullify the Japanese plans this time.
To understand the lessons of this Japanese war, and to teach us how to prevent another, the nature of Japan's strategy during the past 25 years must be analyzed carefully.
Paradoxically, the Japanese began to search for some means of "defense" other than their Navy as a consequence of their victory over the Russian fleet at Tsushima in 1905. The Japanese people gloried in this triumph, but their leaders took a more sombre view. They dwelt upon the fact that they had had to meet two Russian fleets -- the squadrons which were in the Pacific at the start of the war, and a second fleet which arrived in the Far East some months later. If Russia could send a second fleet to the Pacific, they reasoned, then the United States and Great Britain, thanks to their command of raw materials and production facilities, could send a third or a fourth.
During the London Naval Conference in 1935 the Japanese delegate, Admiral Osami Nagano, revealed this reasoning clearly, if subtly, when he said:
Even if the Power with a superior navy sends only a part to engage the inferior navy of its enemy in such decisive battle, the part of the superior navy remaining in other areas will serve as a latent force which constitutes a definite menace, direct as well as indirect, to the defenses of the weaker naval Power. We need only recall the naval engagements of the Russo-Japanese and World Wars to be convinced that this is a truth to which history itself bears witness.
Admiral Nagano had previously declared: "I am not taking into consideration the total force of the aggressor, nor the element of distance. I have put a case in which one nation is actually exerting a pressure of 50 against another which is defending with only 40." This was another way of saying that the United States, if it wished, could overcome the obstacle of Pacific distances and apply a superior naval force against the Japanese Navy in the Far East -- a truism now in course of demonstration. At the time these statements were made, Japan had already decided to relegate her Navy to the place of third importance among her armed forces.
The decision was strategically sound. Air operations of the type Japan proposed to undertake were well suited to the territories she planned to dominate. The Far East is isolated from all nations capable of putting her plans in jeopardy. The distance from the northernmost Japanese main island, Hokkaido, across the Sea of Japan to the Soviet-Korean border and thence through China to Burma is more than 6,000 miles. This "front" could be approached from the west only by a long trip over the Transsiberian Railroad, or by the lengthy "silk route" through the wastes of central Asia, or from India.
From all other directions the Japanese positions could be reached only by sea. The seaward "front" was tremendously long; from the northern tip of the Kuriles, past the Philippines to the eastern extremity of New Guinea, and thence along the outer boundaries of Indonesia to the Indo-Burmese border, is a distance of upward of 12,000 miles. If we extend it to include the islands in the Pacific which Japan dominated at the beginning of the war, we add nearly a thousand miles more. Though the Japanese continental front was fairly defensible, the oceanic front was vulnerable to Allied sea power. The outstanding military-geographic feature of the expanded Japanese empire, however, would be the proximity of the various Asiatic islands to one another and to the continent. The wall of "coastal" islands, extending from within ten miles of Soviet Kamchatka in the Pacific down through the main Japanese islands, the Philippines and Indonesia to Singapore, is broken by only four gaps from 100 to 135 miles in width, and six from 50 to 70 miles wide. The other openings are appreciably smaller, and many of them may be dominated by coast artillery. The development of the airplane meant that the gaps between these islands might be hermetically sealed.
In 1921 the only flaw in the prospective Japanese "defensive" system was that the ocean islands, extending southward from Tokyo Bay to the region of Guam, and thence eastward through the Caroline and Marshall groups, were too widely spaced for the effective use of the land-based fighting and torpedo planes then in existence. Japan could not safely strike until the range of these types of warplanes had been increased. She had to play for time. Her scheme, meanwhile, was to prevail upon foreign Powers not to strengthen their Pacific and Far Eastern bases, and if possible to induce them to freeze the design of their warships so as to keep them as vulnerable to air attack as they then were.
Japan's program for aggrandizement and her quest for invulnerability through air power were hidden throughout the interwar period by a series of contradictory statements, puzzling at the time but now clear. When the Japanese delegates came to Washington in 1921 to attend the naval limitation conference the battleship-airplane controversy was at its height. In England, Admiral Sir Percy Scott was insisting that "the battleship is dead." Admiral Sims, General Mitchell and others were expressing comparable opinions in the United States. There were, of course, contrary opinions -- especially in official naval quarters -- as to the susceptibility of the capital ship to air attack, but the vulnerability of lighter vessels, notably of supply ships and transports, was scarcely disputed.
Japan was already strong in the air and studying the possibilities of air warfare profoundly. A large air base had been established near the southern end of Formosa, only a few hours' flight from the Philippines. Numerous German experts had been brought to Japan. According to official figures, the Japanese Air Force had as many planes or "units" as that of the United States, more than that of Italy, half that of Britain, and somewhat less than one-third as many as that of France, the leading air power of the day. In trained manpower it was the weakest of them all; yet, curiously enough, it had more training units than any other nation. This aspect of the Japanese program was wrapped in secrecy.
In Washington, the Japanese delegation willingly agreed that there should be no limitations on aircraft, but asked for three carriers of 27,000 tons each. Admiral Baron Kato, the leader of the delegation, said he would raise no objection to a proportionate increase in this category for the United States and Great Britain. In abandoning parity in carriers and standard warships he obviously had in mind the possibility of developing Japanese land-based aircraft. Uninstructed public opinion in Japan criticized the naval treaties of limitation, but those who knew the country's real scheme of strategy rewarded Kato for his distinctly "aerial" success by making him Prime Minister.
The use of land-based aircraft and mobile bases -- aircraft carrier forces -- now superseded the Battle Fleet in Japanese plans for war with the west. The world speculated on the activities, actual and promised, of the Imperial Navy. New naval developments were emphasized and "loud-spoken" naval secrecy was imposed. Meanwhile the air arm was progressively though secretly strengthened for its mission. Terminology for the Air Force was adopted which suggested that it was merely a subordinate arm of the Navy. Hypersensitivity began to be shown to foreign air projects in the Pacific area and throughout eastern Asia. Japan refused to be represented at any conference in which aircraft limitations might be broached.
Western suspicion was awakened to some degree by the fact that the economies which the naval limitation treaties had supposedly effected were not reflected in subsequent Japanese budgets. An American aviation journal observed: "As the naval ratio of Japan is, under the Washington treaty, 60 percent of the American naval strength, it may be seen that Japan is spending money on her naval air force far in excess of her allotted ratio of naval strength, aiming in that service evidently at parity with that of the American Navy." [i]
In the 1923 Japanese budget a considerable portion of the sums saved by the cessation of battleship construction were described as appropriated for the building of "smaller warships" -- an elastic term which undoubtedly included aircraft. In that budget increased appropriations were made for gunnery, torpedo practice, anti-submarine and mining operations, and for "scientific research," another phrase which could conceal aerial developments. As in subsequent years -- with rare exceptions -- Japan's direct appropriations for the air arm were remarkably low; the true amounts were obviously hidden under other headings. It was disclosed in 1924 that German-made airplane parts were being assembled in German-controlled factories in Italy for Japanese aircraft able to carry a ton of bombs "from the nearest Japanese base to Manila and return." [ii] Specialists from the Dornier and other German aircraft plants began to supervise the construction of airplane factories in Japan.
The British and the Americans attempted to institute further disarmament talks in 1925. In the United States a Special Naval Board had come to the conclusion that "Aircraft attack, when met by equal aircraft or good antiaircraft guns, will not be able to prevent the transport of troops." [iii] As the fulfillment of Japan's "destiny" was predicated upon troopship movements and the ascendancy of land-based aircraft over carrier-based planes, Tokyo displayed no interest in discussing the subject, particularly since London had become highly sensitive to the question of aerial weapons. Baron Hayashi, Japan's Ambassador at London, preferred that the problem of further disarmament "be talked over slowly." When, however, President Coolidge proposed that reductions of naval armament be discussed separately from questions of land and air armaments, the Japanese responded with alacrity. Yet their approach was odd. Other nations wanted to consider what categories of ships might be reduced; Tokyo concentrated its attention upon what it did not want to reduce, namely, small submarines and aircraft carriers under 10,000 tons displacement. Such carriers are a particularly satisfactory vessel for staging operations.
A remarkably revealing article appeared shortly thereafter in the Tokyo Nichi Nichi stating that "Air forces . . . must assume the important role of tactical [i.e. fighting] operations, while the army and navy ought to take up strategical [i.e. nonfighting] duties, so that they may afford the air forces bases of operations." This article and several others which passed the Japanese censor were critical in nature, calling attention to alleged defects in the Japanese air force, and therefore, perhaps, were officially inspired. For this reason, presumably, they did not receive the attention abroad which they seem to have warranted.
At the London Naval Conference in 1930 the Japanese pressed for the reduction of battleship displacement from 35,000 to 25,000 tons, and for an increase in the age limit from 20 to 26 years, stipulations that would have rendered battleships more vulnerable than ever to bomb or torpedo attack. The Japanese also requested smaller aircraft carriers. At Geneva two years later the Japanese, now in occupation of Manchuria, suggested the complete abolition of fleet aircraft. Their motive is now readily discernible. Since they were prepared to operate from land bases, abolition of carriers would decisively handicap the western Powers.
That year their manœuvres were held among the mandated islands for the purpose of testing "new equipment." This must have largely meant aircraft, and the testing undoubtedly involved the shuttling of planes among the atolls, operations between ship and island, bombing of targets stationed in the lagoons and practice landings. In May of that year a unit of the Tateyama Flying Corps flew in one day from Japan to Saipan and back, with a stop at Chichijima in the Bonin Islands. The earlier flaw in the Japanese strategy caused by the short range of light planes had evidently been repaired. In 1934 Admiral Yamamoto even offered to accept the abolition of submarines, provided the United States and Great Britain would abandon the aircraft carrier. Japan was no longer thinking of fleet action. If she controlled the skies of the Far East, submarines would be as relatively unimportant to her as surface warships. When this demand was refused, the Japanese delegation, headed by Admiral Nagano, quit the London Naval Conference of 1935-36 and Tokyo refused to renew the Washington Treaties of 1922. In March 1939, the Japanese announced a naval expansion program, Admiral Yonai declaring that "one of the governing principles of the Japanese Navy was the maintenance of a fleet equal to that of the strongest naval power." Yet at this writing there is no evidence that after the termination of the naval limitation treaties on January 1, 1936, Japan enlarged her Navy significantly in any category except carriers.
To obtain supremacy in the air the Japanese sought high speed and great range in their planes. The basic theory, propounded by Admiral Baron Kato in 1921, was that rapid concentration of the air forces must be possible. The Japanese planned to hasten their troops to the perimeter of the area they intended to overrun under cover of an aerial umbrella. The Imperial Navy was to coöperate in the conquest by crushing inferior naval forces and furnishing artillery support for landing forces. Thereafter it would in general operate under cover of its land-based aircraft. Its function, a purely defensive one, would be to link the outposts by means of aircraft carrier task forces. These were to be amphibious, in that the carriers would act as staging points for land-based aircraft flying to and from Japanese strongholds. The Japanese were theoretically justified in assuming that such a combination of land and carrier-based aircraft would be superior to hostile warships and aircraft carriers.
In 1936 the Japanese claimed that they had brought out a long-distance plane embodying "new aeronautical principles." Their use of detachable fuel tanks, to obtain increased range, is now well known. Night flying, another element in the plan of achieving rapid concentrations, was emphasized, as was practice in aerial acrobatics. Although Lieutenant-Colonel Adachi had observed in 1932 that "the number of airplanes is less important than their quality," the Japanese seem to have been wedded to the theory of quantity. Their grand strategy was built around large numbers of land-planes which, they assumed, would overwhelm the relatively few planes that could be brought against them by carriers. Japanese fliers were regarded as aerial infantry rather than specialists and, like the expendable land forces of militaristic states, depended for success upon the crushing power of mass attacks. This doctrine probably explains certain of the weaknesses of all Japanese planes until very recently. The bombers and torpedo planes were to prevail by sheer force of numbers; the fighting planes were to depend upon numbers, heavy fire power and the acrobatics made possible by their high manœuverability.
After seizing Manchuria and northeastern China and providing these areas with numerous airfields, the Japanese moved into the next stage in their preparations for war against the United States and Great Britain. The ports of China and French Indo-China were absorbed into the Japanese system. They would thereafter serve as bases and distribution centers, and their facilities would provide aircraft cover for the amphibious moves to come.
The war in the Pacific began with the air attack upon Pearl Harbor, which was followed by the speedy seizure of airfield sites around the perimeter of the Philippines, Indonesia and Burma -- all according to plan. The barrier islands and continental areas from within gunshot of Kamchatka to the Indian frontier became a chain of Japanese airfields; large forces of warplanes could be transferred quickly to any one of them, with a minimum number of refueling stops. Japan acquired an immense potential supply of gasoline, bauxite, rubber -- the essentials for war in the air. She seemed in theory to have attained invulnerability. Allied positions in eastern New Guinea and India were still a threat to her; otherwise Japanese-held territory could not be reached except by slow-moving, seaborne forces, travelling over great distances and depending for protection upon the most vulnerable of all types of warship, the aircraft carrier.
The Japanese had planned shrewdly and well for this war which they hoped to wage by means of a western weapon, snatched from under unsuspecting western eyes. But there are imponderables in war. In the Coral Sea, off Midway Island and in the Solomons the Japanese began to experience them.
American and Allied qualitative superiority in the skies was definitely established. In the Solomon Islands and later in New Guinea the Japanese discovered that the limited number of airfields they had cut out of the jungle did not permit them to concentrate air forces sufficient to contend with the qualitative superiority of their enemies. The mandated islands, because of their smallness, were likewise insufficiently provided with airfields. These regions became bottlenecks. The American strategy of keeping them under steady assault was the equivalent of turning off the valves through which the supposedly overwhelming streams of Japanese aircraft were to flow to threatened points. These checks on the Japanese plan of aerial defense were severe setbacks. The failure of the Japanese Navy to turn back hostile naval forces which included carriers, and its inability to protect its own sea-lanes, as demonstrated in the Bismarck Sea in March 1943, were serious matters also. In these engagements the Japanese were met by forces which they were unable to overwhelm, and by which, contrary to their expectations, they were themselves destroyed or routed. These task force reverses, however, did not impugn the general Japanese strategy.
The battle which followed the seizure of Saipan island by United States amphibious forces was a worse blow. It struck at the heart of Japan's theory of defense of the outer islands. The Japanese carrier task force that steamed out of the channel between Formosa and the Philippines to relieve Saipan was theoretically able to dispatch an endless flow of aircraft, which it would receive from the numerous, well-developed airfields in its rear. The American aircraft opposing it were borne entirely by carriers operating at a great distance from their main bases. The Japanese carriers were supposedly invulnerable, in that they would not need to come within range of United States carrier planes. The fighting range of American planes was, in theory, only half of their full range, since they had to husband enough gas to get back to their carriers. The Japanese seaborne planes were to operate between ship and shore. They could thus take off at points beyond the range of enemy aircraft, deliver their attacks and alight upon islands under American assault, or others in their neighborhood. Then after replenishing their supplies they could deliver another attack and continue on to their carriers; or they could remain on island airfields as replacements.
This important Japanese operation was defeated by American intrepidity, a sufficiency of the right kind of equipment, and skillful tactics. Some American fliers simply disregarded their fuel supplies and pressed their attack straight home to the hostile carriers. We had an astonishingly large number of carriers of our own. And the disposition of American warships and planes was bold and effective. Some American carriers apparently launched their planes directly against the Japanese reserve centers in the Bonin Islands, thus cutting off the reënforcements of planes which were supposed to reach the Japanese carriers. Others kept Saipan under assault and a third group of carriers steamed toward the Japanese carrier force which, no longer "invulnerable," was compelled to retire.
The fact that the Japanese strategy has been sound magnifies the skill and courage of those who have overcome it. American and Allied troops have had to fight bitterly for sites upon which to construct the very airfields that, in principle, should have been there in the first place to protect them. Their airmen have had to struggle against serious odds and to improvise measures against an enemy who had been preparing for two decades. The United States Navy, built to combat other ships, has been faced with the problem of amphibious assault on "unsinkable" and scientifically defended islands and beachheads.
Perhaps the most serious flaw in the theoretically perfect Japanese strategy of conquest and defense through air power has been, in the last analysis, the inferiority of the Japanese fliers. Defective vision and hearing seem partly responsible for this. The Japanese are suffering from having long neglected sound principles of nutrition. Though their aptitude for mastering modern technology cannot be questioned, their fliers seem also to have suffered from improper methods of instruction, coupled with a certain inherited unwillingness to exchange the individual daring of the samurai for the scientific attitude of the machine age. The tactics of air fighting adopted by Japan produce recklessness rather than good judgment and blind courage rather than skill. Their tactics have nonetheless been deemed worthy of official American study. The fundamental reason for Japanese individual and group inferiority in the air can probably be found in the fact that unregimented human beings react more intelligently in a crisis than those who have all their lives waited for orders. Japanese fliers have been commanded to use initiative; such men are certain to come off second best when put up against men accustomed to use their own wits in the face of an unexpected problem almost as instinctively as they breathe.
Tokyo's sole hope now lies in the possibility of destroying seaborne expeditions by means of land-based aircraft. We would be wrong indeed to discount this possibility cavalierly. The size of the fleets which are being thrown into the Pacific -- not to mention the new B-29 Superfortresses -- suggest that the Allied Command, at any rate, is not making that mistake. Henceforth our forces will meet Japanese planes over or near spacious, well-developed territories equipped with numerous airfields that cannot be as readily destroyed or isolated from one another as were the Japanese airfields in New Guinea and the mandated islands. The Japanese can concentrate their aircraft at will in the main Japanese islands, in Korea and Manchuria, and to a lesser degree in the Philippines, Formosa and parts of China. They will be able to attack Allied amphibious expeditions with much greater forces than hitherto. Their airmen will be fanatically determined to reach their targets regardless of losses. And the huge size of our seaborne forces, and hence the more numerous targets offered to Japanese planes, may give added point to the Japanese theory of mass attacks.
The Allies will have the power to assault Japanese territory from numerous directions, and will surely use heavy land-based planes as well as carrier-based aircraft. But the likelihood that the Japanese will be able to launch really powerful attacks upon relatively slow-moving or anchored amphibious expeditions constitutes a hazard that should not be underestimated. The Japanese may be expected to exercise all their cunning in the climactic aerial battles that have been the subject of so many years of thought. They concealed the very fact of their reliance upon air power for a long time; conceivably they may now be attempting to conceal their true strength until a decisive opportunity to use it occurs.
Estimates as to the number of planes with which Japan began the war range from less than 4,000 to upward of 6,000, with a replacement potential of all types of, at the most, 15,000 to 20,000 a year. Recent Chinese reports have raised this figure to 24,000. Certainly, they are substantially higher than would have been conceded a year before the war. The losses to date are a significant indication that production is heavier than we supposed. On June 29, 1944, it was disclosed that American airmen had destroyed more than 12,000 Japanese planes since December 7, 1941. To this total should be added a proportion of the large numbers of planes "probably destroyed," as well as the losses inflicted by the British air forces. The mild interest displayed in the United States in this important item of information was characteristic of our constant underemphasis of the strength of Japanese air power. The figures are shown in their true light if they are contrasted with the statistics of Axis planes destroyed. Shortly before the landings in Normandy, the R.A.F. and U.S.A.F. had shot down and bombed on the ground 26,000 German and Italian planes in the course of the Battles of France and Britain, the North African campaigns, the invasions of Sicily and Italy and the continuous air attacks upon Germany and Nazidominated Europe. The Japanese Air Force has survived losses equivalent to approximately one-half those suffered by the European members of the Axis in the decisive operations mentioned. This suggests a large Air Force and a heavy replacement capacity.
The Japanese are unquestionably bending every effort to increase production of the weapon which they consider so important. Japanese aircraft are produced both in Japan and, since October 1933, in Manchuria. Aluminum in sufficient quantities is derived from minerals obtained in the Malay States and the Dutch East Indies; in the thirties the Japanese discovered aluminous shales in Manchuria and are reputed to have other aluminum ores in Korea. They are dependent upon Indonesia for gasoline, but were working on synthetics before the outbreak of war. How much damage can be done to their aircraft industry by bombings is as yet an open question. We must also take into account that their planes are being armored and otherwise improved; and new tactics may also be expected. The pattern of warfare that has been developed in the Far East in the past is by no means a complete guide to what we may expect in the future.
Finally, we must keep our attention alive to the possibility of future Japanese attempts to use air power for purposes of aggrandizement in the Far East. Developments in aeronautics such as the jet-propelled plane and the robot bomb, and progress in the manufacture of synthetic rubber and gasoline, will be a source of comfort and temptation to those Japanese who retain dreams of imperial glory. Improved dietetics and improvement of health standards may diminish and eventually eliminate some of the physical handicaps of Japanese airmen. And, as was noted above, the weakening of the totalitarian spirit in Japan and the transfer of more freedom to the people might tend to increase physical efficiency and individual initiative and hence produce more proficient aviators. The implications of this ironical possibility need not be surveyed here, but should be kept in mind.
Construction of any type of aircraft in Japan should be totally forbidden in the future. Commercial aviation has been entirely subordinate to military aviation in Japan. If the Japanese are allowed to possess any commercial planes at all, they must be manufactured elsewhere. And continued supervision of all Japanese industry will be required. But the best safeguard against future Japanese aggressions will be our own realization that land-based air power is the decisive military weapon in the Far East, and our awareness that the Japanese understand this fact thoroughly.
Postwar precautions against Japan should include the maintenance of adequate naval strength in the Far East, with proper bases. Starting from scratch, Japan could develop her land and air power much more rapidly than the United States and Great Britain could build new navies, which will always be the sine qua non of the amphibious operations necessary for a counterattack upon Japan. Allied land and air forces should be permanently allocated to the Far East and there should be sufficient air facilities in China and the Philippine Islands. Major American air bases should be maintained in the Aleutian Islands and in Guam, with staging points in the mandated islands. Only a keen and enduring sensitivity to Japanese strategic thought, and the willingness and power to act quickly when it manifests the slightest signs of aggression, can preserve peace in the Far East.
[i]Aviation, January 15, 1923, p. 67.
[ii]Washington Post, July 13, 1924 (quoted in "United States Naval Institute Proceedings," September 1924, p. 1539).
[iii] Report of Special Board, Navy Department, Washington, D. C., January 17, 1925, Section 207, p. 65.