In the current issue of the Supplement will be found a reprint of an article, contributed by Rear-Admiral George W. Melville to the Philadelphia Record, in which he indicates the probable line of development of the United States Navy during the coming decade. The writer strikes the true keynote of our naval policy when be says, Only by right, and not by might, will this nation fulfill her highest destiny; yet we must always bear in mind that it is as essential to be in readiness to restrain by military and naval forces the foes that are beyond the boundaries of a country as it is to effectively control, by local police, the turbulent within a community. In reviewing the causes which have contributed to the remar.kable development of our navy, the first place is given to the attitude and action of the general pi-ess, which has been unanimous in urging the development of our naval power. This advocacy has been supplemented by the lecture field, which has played no inconsiderable part in familiarizing the public with our warships. The ships themselves have been thrown opento the public on every possible occasion, and have greatly conduced to the general interest, as have also the dozen naval stations and navy yards scattered along our seaboard. There are ten shipbuilding firms that build battleships and armored cruisers, over fifty firms that can turn out a gunboat, and several hundred firms that can manufacture naval stores and supplies, and all of these have at least a financial interest in the enlargement of our fieets. The army of tourists and commercial travelers who annually go abroad ; the commercial and maritime associations of our leading seaports, and the shipping interests in general are other infiuences that have worked strenuously toward the same end. Lastly, it must not be forgotten that every Secretary of the Navy and every President, for the past twenty years, has urged the progressive development of this branch of the military service. The annual appropriation has gradually increased, until now it is nearly treble what it was five years ago, the estimates submitted this year calling for about one hundred million dollars. Our readers will remember that the SCIENTIFIC AMERICAN has always claimed that the possession of the far-distant Philippines, with their thousands of miles of coast-line, must, of necessity, be the dominant factor in determining our future naval policy, and we notice that Rear-Admiral Melville is of the opinion that it will be near the Philippine Islands that we shall have to fight our future decisive battles. It is certain, he says, that we must eventually renounce all sovereignty of the Philippines or else prepare ourselves to hold these islands against an efficient naval power whose base of operations may be much nearer than our own. For this reason he urges that we should establish in some harbor in the Philippines large engineering shops, where machinery could be built or repaired and warships docked and built. Other arguments for an increased naval establishment are found in the construction of the Isthmian canal, which, however strongly fortified, would require a powerful navy to insure its safety and neutrality when completed. It is the opinion of the writer that before the end of the present decade we shall rank next to England as a sea-going power, and he suggests that in view of the fact that we may be suddenly required to increase our naval force, it might be the proper thing to make a wholesale purchase of warships from some nation that has greater temporary need of gold coin than of steel guns. We agreewith the Admiral that every increase in the strength of our navy undoubtedly makes: for. the general peace of the world. As to the constructive and mechanical progress of the future, development will be in the direction df making the individual unit more formidable, and. ships will be built more rapidly. Hitherto it has taken five years to design, build and commission a warship; and unless the private firms are going to show greater celerity in completing their contracts, the government may undertake the task of building its own warships, something, by the way, which we think the government ought in any case to do, if it would safeguard the interests of the navy. Armor will continue- to improve, and it. is probable that in addition to the two establishments that now turn out first-class armor a third firm will SOOU be in a. position to compete for contracts. There will be a change in the size of the main battery of warships. Admiral Melville contends that the 12-inch gun is teo heavy and cumbersome for existing needs, and that the new 10-inch weapon, which is more powerful than the 12-inch gun of five years ago, is the largest piece that should be mounted on a modern warship. He also draws attention to a phase of the armor and gun controversy which has not been investigated to the satisfaction of naval engineers, although they have called attention to its importance, namely, the indirect damage within the interior of the ship by the impact of 8-inch or larger shells upon armor which they fail to penetrate. The continued impact of heavy shell upon the armor protecting the machinery compartments will, Admiral Melville considers, be certain to disable some important auxiliary engines. Moreover, the effect upon the hull itself may be greater than is anticipated. Structural and machinery steel will withstand strain and pressure, but it will not resist shock, and not only will the auxiliary connections in the way of piping and electrical conduits be damaged, but it is extremely probable that some sections of the hull riveting will be greatly impaired, since experience has shown that the rivets can lie easily sheared by shock. This last point is unquestionably a most important one, and we have recently had practical evidence in the high-explosive shell tests at Sandy Hook, when 12-inch armor supported by a section of the side of the Iowa was attacked, that the structural material of the steel backing, even where penetration is not effected, will suffer serious injury, just where Admiral Melville indicates, by the shearing of rivets and opening up of joints. At the same time, we are free to admit that the point thus raised somewhat nullifies the Admirals advocacy of lighter guns; for the racking effect of a 12-inch gun is enormously greater than that of the lighter 10-inch piece which he would substitute for it.