OUR ENEMIES IN THE AIR.

Bruce Herald, Volume LIV, Issue 51, 8 July 1918, Page 6

OUR ENEMIES IN THE AIR.

GEBMAN FIGHTING MACHINES.

INGENIOUS EQUIPMENT DEVICES

Once an idea, is incorporated in a fighting aeroplane, it is only a question of time when the enemy discovers it, owing to the machine falling into 'his hands. Consequently the Allies know •most of the Germans' "secrets" of the air, just as the Germans Icnow theirs. Each side is 'continually investigating the other's'aeroplan'es. It seems as though military'machines will remain extremely 'difficult or 'dangerous' to' operate for all time, because any weight which might be allowed for devices insuring 'ease and ..safety of flight must 'be immediately commandeered for such necessary fighting requisites as mac'hine guns, ammunition, more speed and greater climbing ability.

At present (writes C. Dieutsbaeh in the Scientific. American) the Germans are making their reconnoitring two\nien type and the bombing three-men type 'comparatively .small and fast, following the practice of the smaller or ■chaser planes. In the ease of their largest and slowest .machine, the Gotha bomber, which is named after the location of the factory, where it originated, speed and manoeuvring ability are backed' up by an improvement in the armament. In- this bombing machine practically all "blind areas" or "'dead angles" of fire have been eliminated by mounting a third machine-gun under the fuselage, vv J hi'ch is shaped like an inverted channel or floorless tunnel, so that its fire can be brought to bear on a.ll points heretofore in line with the tail members. In other words, the "blind spot" formerly 'existing under the tail'of an 'airplane and taken advantage of during a combat lias now been eliminated in the Gotha bomber. COMFORT AT 'A DISCOUNT.

The only concession to the 'German aviator's 'comfort is, in all types, the commendable practice of carrying the exhaust from the engine beyond any possibility of mixing with the air he breathes. And well that may be so; for the physical condition or efficiency of the airmen is still more important than that of tire machine; and the, Germans have also recognised that on a fighting plane one man must essentially be capable of 'doing the work of two, and 'do it well. Again, the inert weight of t&o much' personnel cuts down war efficiency 'even more than needless weight of machinery. 'As the requirements of an ideal l warplane have 'been gradually revealed in the 'Course of the long war, the purely aerodynamical advantages of the monoplane —'more lift and 'less drift of the wings themselves—'dropped more and •more-in the- estimation oft the designers. In- the 'complicated 'maze of 'compromises that go to solve the warplane design, the structural advantages of superposed wings—more surface and strength, less size land 1 weight—came to "the front. To-day the biplane rules supreme, but triplanes and' multiplanes •may yet offer the acme of military efficiency.

17,000 FEET UP AND 125 MILES AN HOUE. Something of ithe spirit of German' military 'aviation mi'ay 'be 'gleaned' from the reports of Grerman journalist's who were recently invited to visit the flying grounds of Doeberitz, near Berlin. Indeed, .more ean perhaps toe. learned from 'these reports than from the flying

machines and flying men wlio 'have from time '>to time fallen into Allied 'han'ds, just as Wilbur Wright, in 1905, remarked 'to the writer: "If a perfect flj'ing 'machine were dropped on 1 to the e'art'h it would not help men to fly." ■Altitude recorders 'are mado to register up to 17,000 feet, and speedometers up to 125 miles per 'hour on the new German airplanes. Types lare quite numerous and 'highly specialised for their different tasks, such as reconnoitring, artillery control, bombing and cihasing.

WIRELESS ON WARPLANES

In November, 1915, all German, warplanes were equipped with wireless telegraphy, The apparatus' employed weighs 701b, and 'has a range of 50 miles. It 'transmits and' receives equally 'well; in truth, this probably explain's the secrets of the manoeuvres in squadron formation of the German raiders over England, particularly in the latest .raids. The reception of wireless

messages aboard noisy airplanes, as is well known, is. most 'difficult; but the Germans appear to have isolved the problem with the Makrophone, a device Whic'li highly intensifies 'the sounds in the receiving telephone and makes them clearly audible in spite of the engines, vibration 'and wind. The generator employed with the wireless equipment is put to good use during cold weather or when flying at great altitudes in 'heating resistance wires woven into the aviator's 'clothing-. Thus ho is kept warm and in full possession of 'his faculties, icven in the paralysing cold of 'high altitudes, which penetrates the .'heaviest wraps. BOMBS AND 'BOM'B SIGHTS. Some German raiders carry bombs of over 6001b weight. In the sighting of bomb hits the Germans have made con-

tinual progress, and to-day they are employing highly efficient sighting instruments mad'e by such well-known optical 'concerns as Zeiss and Goertz, which have enlisted all their skill in this direction as well as in 'aerial photography. The latest German bomb sights em-, body only one new principle in advance of what was 'demonstrated' long ago by Lieutenant Scott; but they ;are most ingenious' in the matter of mechanical computations, and in. this respect not unlike the cash register. Thus sighting becomes simplicity itself. The air bubble of a fluid level' is optically made to 'appear as a slender dark circle in the field of sight, and the marksman has only ta point his long telescope so t as to keep this ring central in the field and surround his target to know that the telescope points in the 'direction of gravity, or truly vertical. But this single vertical telescope is also made j to sight objects iat an angle ahead or | sidewise, by urieans of a universally jointed prism next to- the lowest lens. This prism is operated by a mechanism next to tire eye-piece, which' registers on.a dial the number of degrees that the prism has been the line of sight. Sighting the same objective first at an angle 'and' then vertically, after 'making ; a.n 'altitude adjustment, shows the speed over .the ground on a 'chronograph. / That reading, deducted from, the;reading on the propeller's revolution- 'counter; the speed of the head windI—'exact 1 —'exact 'bombing must be done dead against the wind; the 'altitude: as given hy the barometer, minus the altitude of the 'target 'above sea.lev el j en-, ables'tho marksman to read from a table wi/at angle 'corresponds to these; three particular figures, and by which he 'must sight, his target ahead through the prism at the'.imoment of the bomb's

release. The new (principle, therefore, is the 'consideration of the wind's speed 'and drift, though with heavy bom'bs of proper s'hape that is not only the most uncertain, but also the smallest factor. TEE 'ARTIFICIAL EYES.

There is on'e German optical device which might s'hed some light on the efficiency of the "aces'" Immelmann and Boelke and their .emulators—a photographic machine gun wlndh is employed in aerial sham battles, and Which takes a, photograph of the attacked machine at every shot, showing 'by its position in the field of isight exactly 'how eadh shot, if real, would 'have thit or missed. '

Another German device is the air scout's artificial eye. This is a double stereoscopic camera.' of 'the utmost power and sharpness, 'built into the 'body at a point where, superior to the human eye which is placed 'behind the propeller, motor and front planes, it commands an unobstructed view of the ground below. This cam'era has to be stereoscopic for the same reason that our eyes are stereoscopic—in order to reveal the true nature of things. With its powerful lenses it discovers, from an altitude of two miles, whether the trenches it snaps are actual or only shallow forgeries". 'Sham batteries are likewise 'detected; for this camera shows everything in true relief as against the usual flatness of photographs. This camera also permits 1 the air scout to photograph the whole territory flown over in a continuous series of picture. AIR CANNON AND MACHINE " 'GUNS.

At the recent inspection of the German air fleet by the German journalists l , firing from airplanes with machine guns and with small one-inch semi-automatic eannon was also demonstrated. The machine guns use the tracer bullet, which leaves -a luminous' wake behind it. Incendiary bullets, too, 'are used, and during the idemdn'straticrti'S ■& number of targets were set oh fire" by thes'e phosphorus missiles. Steady improvement has resulted in a high de« grce of re'liability in .German' aerial armament; so much so, in fact, that failure of mechanism during 'actual combat is the exception rather than the rule, in sharp 'contradistinction to the early 'days of the war.