the Southern commerce destroyers prolonged the losing struggle of the Confederacy by so much as one day, nor would the result of the war have been different had there been a hundred Alabamas -so long as they were used purely as commerce destroyers. The permanent decline of American maritime commerce was due much less to commerce destroying than to legislative, economic and fiscal causes subsequent to the war. In the Spanish-American War neither combatant had a merchant fleet worthy of the name, and so it affords no examples of war on commerce, though our men-of-war, of course, captured such Spanish merchant ships as came their way. The war was in effect concluded by the destruction of the Spanish fighting squadrons at Manila and Santiago. In the Russo-Japanese War the Russian division based on Vladivostok made several raids on Japanese commerce, in one case getting as far down as the entrance to Tokyo Bay, but the influence of these raids on the final result of the war was absolutely nil. The Japanese refused to draw any part of their main fleet away from their strictly military objective-the Russian fleet of fighting ships in Port Arthur. Even in this mere outline sketch of commerce destroying in past wars, it may be seen that certain facts repeat themselves with such consistency that we can but conclude that they belong to the constant teachings in the school of history. We see that commerce destroying has ever been used by the nation having the weaker navy-weaker in fighting ships, in morale, or in the willingness to run the legitimate risks of normal war on the sea; that the main incentives to such warfare are economy and the longing for an easy way to success in war; that the surest way of accomplishing the ruin of an adversary's commerce is to destroy the fighting force that protects it, rather than to make direct war on commerce; that commerce attacked directly sometimes actually increases in war, when protected by adequate fighting ships properly used; that, at its best, commerce destroying has been able to inflict no more than a small percentage of loss on an enemy's total maritime commerce; that the monetary loss to an enemy caused by attacking her merchant ships has never amounted to more than a very small fraction of the cost of war; that an enemy country has never been brought to the verge of bankruptcy through attacking its commerce; that war on commerce has never produced concrete results of moment tending to reduce an adversary to a state of impotence; and finally that commerce destroying has consistently been practiced by the nation that was, sooner or later, defeated in the essentials of the wars in which this form of warfare was employed. It is hardly within the bounds of reason that the foregoing clearly discernible facts should have been merely coincidental. There must be some reason for the results, and when these results are similar again and again this reason must be fairly constant, if not fundamental. The results in war are after all the essential things, and when a mode of warfare fails to produce results the reasons for its adoption cease to be of particular interest. So it is beside the question to advocate commerce destroying in war on account of its original economy, for on the whole its operation is very uneconomical, looking at the war as an entity rather than as a number of parts; it is of no moment to state that war on commerce will reduce an enemy to bankruptcy, since it has never done so; it is futile to the extreme to employ such warfare hoping to win victory thereby, since the history of a hundred and fifty years and more show it to have been ever associated with defeat. It is not intended that the conclusion is to be drawn that the final results of the various wars were absolutely determined by the types of naval warfare employed, but beyond question the successful use of sea power did have a great influence in each case, and direct war on commerce does not seem to be the most advan tageous use of sea power. Since the war is conducted by force it must be terminated by the destruction of force, and so far no easy method of accomplishing this has been evolved. War on commerce has its uses, for it annoys and weakens an enemy, but as a primary, peace-compelling undertaking it does not produce military advantages of importance. The best way for a combatant nation to protect its own commerce and at the same time drive the commerce of its enemy from the sea, is to destroy the fighting ships of that enemy. That much is certainly true if we are to accept the lessons of history up to the present time, and we are safe in assuming that it will remain true until basic conditions have changed or some new method or instrument in commerce destroying is utilized that fundamentally changes the problem. It may be well to inquire here if there is any property of submarines that indicates that their use as commerce destroyers changes, to any great degree, the general problem of war on commerce as practiced by various nations for a hundred and fifty years. From a superficial examination it would seem as though such were the case, but upon deeper inquiry the effectiveness of the submarine as a commerce destroyer is found to be much more apparent than real. The ability to submerge is an advantage in that it aids in concealment and protection, but at the same time it enormously decreases vision and speed, both very essential for effective commerce destroying. On account of the physical limitations of submarines they are easily injured or disarranged and a slight injury or disarrangement may be fatal. Compare the relative effect on a submarine and on a fast cruiser of to-day or a fast frigate of the past, of a shot hole, or a steel net or slight disarrangement in motive power, and the limitations of the submarine as a commerce destroyer are at once apparent. The ease with which she may be damaged even by a merchant vessel, very materially limits her ability to board and determine the character of a suspected vessel, and in even moderately heavy weather she is badly handicapped in every way. The size of crew carried by a submarine makes it impracticable for her to send in prizes under prize crews. She can only destroy her prizes. Thus while she can subtract from the wealth of her enemy, she cannot add to that of her own country. A commerce destroyer has always to keep careful watch for two thingsher prey and her enemies, to capture the one and to evade the other. To enable herself to evade, the submarine has necessarily to reduce her ability to capture. Certainly up to the present the submarine has not demonstrated that it has changed fundamentally, or even in marked degree, the problem of commerce destroying. The general non-military opinion as to the effectiveness of the submarine as a commerce destroyer is largely due to the fact that submarine exploits have been considered by the newspapers to have great news value and have been featured because the submarine was a new instrument of war, its employment in commerce destroying was unexpected and its humanitarian side gave to it an interest that its military accomplishments did not warrant. If financial loss be made sufficiently great and sufficiently widespread to bring suffering or extreme deprivation upon many individuals it may have military effect by damping the general zeal for war or even by arousing a willingness to make great concessions for peace. In the case of the financial losses here considered, we have seen that the very interests that suffer the losses are the ones that to a certain degree have these losses compensated. In this age maritime losses are very generally distributed by means of insurance, and there are no indications of real suffering brought on by maritime losses at sea. The effect of this form of warfare on the morale of those practicing commerce destroying is, of course, speculative, but it is highly probable that a navy that systematically practices war on defenceless merchant ships almost exclusively for any length of time will deteriorate in those characteristics that distinguish virile, courageous, manly naval personnel. When the French Navy was for so long practicing direct war on English commerce, the morale of her navy was at its lowest ebb. That this was not racial is at once apparent when we recall that during this same time the morale of the French army was above reproach. We know that heroic action develops the capacity for heroic action, and the development of military character is very largely dependent upon the nature of the service one is required to render. Though possibly not strictly within the scope of our inquiry, it may be of interest to note that friction with neutrals is one of the historic corollaries of war on commerce. It is not difficult for one warring on the commerce of an enemy to convince himself that an occasional attack on a neutral will produce results of benefit to his country, and such attack is so easy, and resistance so futile. Of course, such attacks may be of use in specific instances, but the resulting resentment of the neutral, if nothing more, is bound to react to the advantage of his enemy, particularly if that neutral is of importance in the family of nations. Especially in this day the good will of neutrals is an asset of considerable importance to a belligerent, and war on commerce is a very likely way of alienating such good will. NOTE. Various naval authors have been consulted in preparing the first part of the above, particularly Mahan, Darrieus, Daveluy, Corbett and Thursfield. [COPYRIGHTED] U. S. NAVAL INSTITUTE, ANNAPOLIS, MD. DETERIORATION OF STEEL PROPELLER SHAFTING By COMMANDER C. H. J. KEPPLER, U. S. Navy A remarkable instance of pitting of steel shafting after only seven months' service was disclosed recently upon the docking of the U. S. S. New Orleans at Navy Yard, Boston. The New Orleans is one of the older types of protected cruisers, of about 3400 tons, and is sheathed with copper. About the middle of July, 1917, the installation of new propeller shafts was completed at the Navy Yard, Puget Sound, but the urgent war requirements did not permit encasing the steel shafting with the usual composition sleeve. The tail shafting, a hollow steel forging 13" at its greatest diameter, has a section 30' 8" long between the end of stern tube and forward edge of strut bearing, which except for the protective coats of paint was directly exposed to the sea water. Upon examination in dock on February 16, 1918, the surface of both shafts was found to be covered with innumerable, deep, irregular pits, some areas of from 10 to 16 square inches and from " to 3" deep (see Fig. 1). Near the struts and stern tubes, under the fair-waters, positions nearest the copper sheathing of the hull, were found the deepest and most numerous holes. The steel fairwaters were honeycombed with large holes and the zinc plates had entirely disappeared (see Fig. 1). A black oxidized metallic substance in the deepest pits was removed with scrapers and had the consistency and appearance of soft putty mixed with lampblack. A chemical analysis of this material gave the following: (a) Ferrous Oxide, 35.3%. (b) Ferric Oxide, 30.5%. (d) Undetermined, 18.2%. Ferric Oxide is probably FeO to Fe,O, after exposure to air. FeO is probably hydrated Ferrous Oxide. |