NIGHT-FLYING

Dominion, Volume 11, Issue 204, 17 May 1918, Page 5

NIGHT-FLYING

HOW THE AIRMAN FINDS HIS

WAY.

There are few questions a night.'flying airman, is more often asked by laymen friends than the easily answered one: "How do you find your way at night?" The answer is: "Just as one does by daylight—by looking!" On a moonlight night an airman can see almost as much as he can in the daytime. From a considerable height villages, roads, canals, railways, and even farms, groups of buildings, and such small things as bridges, factories, and trenches are distinctly visible. The oidy differenco from daytime visibility is that tho airman cannot see so far, his range of vision being limited, except for large objects, to three or four miles, which is amply sufficient' for ordinary navigation given normal intelligence, good maps, and a little experience On dark nights considerably less can be observed, but forests, canals, towns, rivers, roads, and railways can be seen within a radius of about a milo of the machine, and oven without the use of instruments the course can generally -bo followed with ease.

Some airmen rely chiefly upon their compass, knowing before they leavo their aerodrome their course and the strength and direction of the wind and how they will have to steer to allow for the "drift." . They then merely use landmarks as checks to their compasses. Others rely chiefly on following the country and seeing prominent landmarks, especially when the district is well known t<s them, and only use the compass, or tho nioro reliable North Star, as an occasional rough chock. Tho most conspicuous of all landmarks in any weather is water, especially in the form of canals or rivers, a fact which renders very easy the Germans' task of finding London on moonlit or dark nights. Tho aurora borealis is not necessary to assist them'. They know when tliey leavo their coast that they are certain to seo our coast-line, however dark the night is, and that by following it northwards or southwards, as the case may be, they will come to the estuary of the Thames. When that is found the rest is easy. The difficulties of navigation, howover, do not end with the finding of the objective and the dropping of the bombs. Tho airman has to return 'and find his. aerodrome and land; and It is here very often that the difficulties begin. Aerial lighthouses are greatly used for this purpose by the Germans. Each lias a different code, like ordinary lighthouses for sea navigation, and can be scon easily'twenty miles off on a clear : night. They also use ttieir "green-ball" machines for navigation and fire a fixed number of "balls" on a chain, every five minutes at certain iixed places. As these mount to 10,000 ft. it is highly probable that those fired from tho Belgian can actually bo seen by German machines high over London, who then have only to steer in tho direction of theso recurrent signnls to "hit" their const at a known spot. It is also possible that the Gothas will use tho Zeppelin system of navigation by what_ is known as "directional wireless. An airship over Gravcsend can "call up" the wireless, station at Heligoland and ask for its hearings or direction. Tho operator at Heligoland by means of higenious instruments, can tell in what direction the airship lies by the varying sound of the signals in ilio telephone receivers over his ears when ho moves certain levers. He can then sond a messago to tho airship giving him his "bearing" from Heligoland. The Zeppelin commander can then make similar inquiries from u station in Belgium and can draw two lines on his chart showing tho bearings given by the two widelyseparated stations, i.nd the intersection of tho two lines shows him immediately his position over England within a .very few miles."-By "Paul," iu the "Daily Mail." J