258 TRANSACTIOXS OF SECTION G. 



by the Board of Invention an'l Research. By its means tlie position 

 of a submarine explosion off the coast of Belgium could be found within a few 

 hundred yar<ls by observers on the Ensilisb. toast ; passing ships or submarines 

 could also be identified and located. Sounfl ]ocator.= were also uised on board 

 anti-submarine craft, but at the time of the aimistice were for this purpose 

 being superseded by other methods. 



Mine construction, laying and sweeping formed the object of many successive 

 improvements. Mines of special construction, which cannot be swept by ordinary 

 means and which explode without actual contact, were used in large numbers in 

 1918, and were particularly effective against submarines. Various new types 

 of oscillating mines were also dtvelopecT. 



Many of the newer fighting units of the Navy were designed for speeds far 

 in excess of anything that had been pi-eviously contemplated; the attainment 

 of the required horse-power was rendered possible by improvements in boiler 

 construction, by the development of oil-firing, and by the invention of the geared 

 turbine. At the nresent time the horse-power of some of the fastest destroyers 

 equals that of any pre-war Dreadnought. 



Numbers of strange craft were designed for special purposes. The monitor 

 was used a? a floating fortress, and ships without funnels or masts formed 

 cruising aerodromes. The torpe^do net was known to be ineffective as well as 

 inconvenient, but some years elapsed before ships were rendered immune to 

 torpedo attacks by a wide outer sheaf of resilient construction. Some protection 

 was first given to mine-sweepers by fitting the vessels with a false prow ; the 

 newer mine-rweepers were rendered nearly imsinkable by the provision of 

 numerous bulkheads. The submarine was developed with regard to size, range, 

 and speed. The latest and perhaps the strangest craft was the submarine fitted 

 with a heavy calibre gun which could be fired when all but the muzzle was 

 submerged. 



Aircraft. — The rapid progress and expansion of aeronautical science and 

 construction is perhaps the most remarkable achievement of engineering during 

 the war. 



In 1909 Bleribt flew the Channel. In 1910 Codv won the British Michelin 

 OuD by a flight of 185 miles. The Uoyal Flying Corps was formed in 1912, 

 and it was decided that the equipment should consist of seventy-two aeroplanes 

 and two airships. The number of aeroplanes available in 1914 was under 200 ; 

 the number ultimately required proved to be more than 3.000 per month. The 

 aeroplanes which were sent out with the Expeditionarv' Force in 1914 had a 

 maximum speed of some 80 miles per hour, a rate of climb at gi'ound level of 

 300 or 400 ft. per minute ; thev were equipped with engines of 60 to 100 horse- 

 power. In 1918 the fa^t jnachine had a maximum speed of 140 miles per hour, a 

 rate of climb at sround level of 2.000 ft. per minute ; single-seaters were fitted 

 with engines of 200 to 300 horse-power, and the largest machines were equipped 

 with a power plant developing over 1,300 horse-power. The maximum heigh'; 

 attainable had increased from 5,000 to 25.000 ft. 



The Atlantic flight has given the measure of the success aehievwl in the 

 design of long-range bombing machine^s. Two types were evolved : the fast 

 dav bomber, capable of carrying a useful load of about 3.000 lb. at a spee<l of 

 130 miles an hour, and the night bomber with a larsrer load and slower speed. 

 The largest aeroplane manufactured in numbers was the Handley Parrp V/1.500. 

 with a weight of 11 tons and a |xiwer plant of 1.300 horse-power. Three davs 

 befoi-e the armistice tv.'o of these machines stood fully equinped waiting for the 

 order to start for Berlin. The largest bombs in use weighed over a ton, and 

 during the war 8.000 tons of exnlosives were dropped on the enemy. The 

 experience which they had gained in the construction of the high-powered engines 

 required for airship work nroved to be a valuable asset for the Germans. Initially 

 also their rate of production, both of aeroplanes and engines, was far superior 

 to ours, and, faced with the menace of otherwise being for a period deprived of 

 machine's, we were bound to continue the use of certain standardi.=ed types 

 longer than was desirable. 



The lahonr difiicultv was ovprcome by the intT-oduction of a large proportion 

 of female labour, which proved to be very suitable for aeroplane manufacture, 

 and especially for wine: construction. The bulk production of aero-engines pre- 

 sented grave difficulties. Evei-y part had to be made to close limits so as to 



