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THE landsmans log will fail of its purpose if it leaves an impression that target and battle practice with guns big and small constituted the whole of the activities of the Atlantic fleet on the Southern Drill Grounds. Nor must it be supposed that the gunnery consisted exclusively of firing by individual ships against individual targets. Every probable variation of war conditions was reproduced. I have a vivid recollection of the particular day when a division of four ships left the fleet, steamed in column until they were hull down, then turned, simultaneously, four points to starboard, and, moving at high speed in echelon, or diagonal, formation, delivered their broadsides upon a single target 9,000 to 12,000 yards distant. This maneuver, Heen, as I sa w it, on a glorious September afternoon, was a most stirring and picturesque naval spectacle-with fifty square miles of the sapphire-blue ocean for a stage and ten thousand men on a three-mile line of battleships for audience; Two or three points off the starboard bow of the “North Dakota,” and some four miles distant, was the target, which was being towed at ten knots on the same course that we were following. Abreast of us aIid five hundred yards to port was the “New Hampshire,” flagship of the Second Division, and,' ship beyond ship, I could see the other eleven battleships steaming abreast, each like the “North Dakota,” crowded on its bridges and forecastle deck with eager spectators of the attack. The firing division, six miles distant from the target, was s ome seven miles off the port bow ; f the farther pnd of our line. And so, from the observing fleet, we watched the four ships maneuver, now firing at the extreme bearing, for th' whole broadside, forward, then turning to bring the batteries to the extreme bearing aft -- and throughout it all, at the target, there soared majestically skywai'd those snow-white columns of water that told of the accuracy or otherwise of the shooting. On other days individual ships would attack two widely separated targets at once-and again, ships would be sent out at night to try their 12-inch batt8ries upon targets that were 9,000 yards distant; while throughout all these operations the corps of wireless operators were working out special problems relating to their own special work, and particu],arly with respect to “interference." Every era of naval history has been fruitful, in varying degrees, in novel inventions and improvements and the many new problems which they have inevitably introduced. High explosives, electrically-operated mines, smokeless powder, the rapid-fire, high-velocity gun, the automobile torpedo, the torpedo boat, the destroyer, and the submarine have each in turn exercised their powerful influence upon the design and maneuvering of ships. To-day there has appeared a new engine of warfare, more puzzling than any of its predecessors, because, unlike them, its opel ations are not confined to the sea, but have invaded an entirely new element-the air. Although tho attitude of the Navy Department toward the so-called “aeroplane warfare” is conservative, it is by no means reactionary. While it is realized that much of the speculation as to the offensive capabilities of the aeroplane is premature and not justified by the present state of its development, naval men concur in the belief that, when a suitable type of machine has been evolved, the aeroplane will play an important part in the strategy of the future. This conviction has been deepened as the result of the experiments carried Qut hy Ely and Curtiss in the effort to produce a machine suitable for naval scouting. The Curtiss “Triad,” as it has been called, has shown that it can start and alight from a calm sea, and the work of this remarkable machine, following the feat of the late lamented Ely in alighting on the deck of a warship and starting therefrom, which has been repeated on other occas ions, has carried the aero]lane scout a long step forward toward the stage—still a long \yay distant-when it can be regarded as a perfectly reliable medium for naval scouting. The exigencies of naval warfare demand that the aerial scout shall be capable of starting on its mission and gathering and transmitting its ob-servations in any weather. With the present form of pontoons this is impossible; and it is difficult to imagine any form of sustaining device that would carry an aeroplane over the waves of a rough sea at the speed which is necessary for flight. It is possible that the solution of the difficulty will be found in the construction of special aeroplane tenders-high-speed vessels, with long, unobstructed reaches of deck, suitable as starting and landing places for the machines. Such vessels, if they were provided with large rudder area and designed for unusually quick maneuvering and rapid changes of speed, should be accessible for the safe return and landing of aeroplanes, even in consideralle stress of weather. But to return to our log, which, if it is to be true to its name, must contain a record, not o· theories and November 2.5, 1911 SCIENTIFIC AMERICAN 479 opinions, but of the actual work of the Atlantic fleet on the Southern Drill Grounds, as seen by civilian eyes, and of the impressions which it has left upon the civilian mind. One of the most instructive and novel of the many visits paid to other ships of the fleet was an early morning trip to the “Michigan” for the purpose of witnessing aerial target practice. On mounting the gangway we found that the quarter deck had been turned into a veritable kite factory. Yards of red bunting, reels of wire, and a plentiful supply of light pine scantling was in the process of being built up into a number of box kites and several square targets measuring each about twelve by fifteen feet. Now the handiness of the sailorman is proverbial; but I never knew till I got aboard the “Michigan” that he was an expert kite builder, and since I am perfectly certain that the building of box kites is not to be found in the curriculum at Annapolis, I may be pardoned my surprise and appreciation at seeing a stalwart lieutenant, armed with hammer, pliers, and a bag of wire nails, knocking a box kite together with as much facility as he would handle a sextant or a range finder, plot his ship's course, or bring a 20,000-ton battleship to her moorings. The box kites completed, they were flown in a group of three from the stern of the “Michigan;” and after much hauling and slacking, and, or shall we say “backing and filling,” were coaxed out of the bewildering cross currents of air, which formed the aerial wake of the ship. into the light and steady breeze which was blowing. The end of the cotton rope to which the kites were attached was made fast to a steel wire, which led through a haul-down block up to an extemporized winding drum, at the head of the port gangway to the boat deck. As the wire was paid out, the targets were attached to it in the position shown in our engraving, and when they had been lifted to a height of some 300 feet above the water (the limit of the lifting power of tbe kites in the light air which was blowing) they were ready for the firing. Two ships had been delegated to the work of destroying the enemy; and as soon as the targets were ready one of the “Connecticut” class of battleships steamed rapidly out from the fleet until she was abreast of the' targets and about 2,000 yards distant therefrom. She opened fire with her starboard battery of 3-inch, 14-pounders; fired some two or three dOlen rounds; and then steamed in at full speed to take a closer look at the targets and see how often she had winged the enemy. Not a single shot had found the mark! Then the four-funneled cruiser “North Carolina” drew up abreast of the target and opened fire with a ranging shot which missed. The second shot struck the piece of scantling which was fastened across the top of the target, cutting it in two and allowing the cloth to droop in the center. The effect on the firing was instantaneous; for, the range being no,w known, the gunners put shot after shot through the squares, making a total of about a dozen hits. The different results accomplished by the two ships showed clearly the need for some form of tracer, such as I described In the last section of the log, dealing with night fring, to show the the course of the shells through the air and enable the sight-setter to make the proper corrections on the sight bars. During the progress of th"e firing, the ordnance engineer of the “Michigan,” who had charge of the kite flying, drew my attention to a phenomenon, which he suggested would form an interesting subject of speculation for the readers of the SCIENTIFIC AMERICAN. He asked me to note that after a 3-inch gun was fired, two distinct reports of the discharge were noticeable-one ! sharp characteristic snap, which seemed to come from the locality of the target, and the other a more muffled report which reached the ship a few seconds later. The sharper report, by my timing, reached the “Michigan” in about 2% seconds' time; the second report in about 5% seconds' time. Now the velocity of the shell when it leaves the muzzle is about 2,800 feet per second; the velocity of sound is about 1,140 feet per second. The distance from the gun to the “Michigan” and the target (which was about 300 yards astern of the “Michigan") was about 6,000 feet, so that the sharp report traveled to the ship at the velocity of the shell and the duller, muffled report at the velocity of sound. Now here is a pretty little problem in acoustics which we present for consideration. How came it that the first report of the gun reached the ear in about half the time that it should have taken, by all "The ordinary gun mount on board ship allows an elevation not much above 15 degrees. For successful defense against aeroplanes, a higher elevation is necessary." the laws of acoustics, in making the journey? Some one on the ship suggested that the first report was due to the noise of the shell as it passed the ship. But the “scream” of a shell is continuous, rising to its maximum intensity as it passes the listener, and dying away as the distance increases. Another suggestion was that a part of the sharp sound wave of explosion traveled in the attenuated air immediately behind the shell, being, in fact, “paced” by the shell, and that this portion of the air wave was sufficient to produce the loud, snappy effect above referred to. The ordinary gun mount on board ship allows of an elevation not much above 15 degrees. For successful defense against aeroplanes, a higher elevation is necessary, and an experimental one-pounder is now being developed by the Bureau of Ordnance which, at an elevation of 45 degrees, will throw its shell to a