AIR BEACONS.

Thames Star, Volume LXIII, Issue 17579, 19 March 1929, Page 6

AIR BEACONS.

Whilst Sydney’s suggested air beacon is certainly a step in the rightdirection, it cannot be considered remarkable compared to existing beacons in Europe and America. For example, tlier are at- least seven powerful beacons between Croydon and Paris, carefully arranged so that by night’, at least one of them is visible aivvwhero along the route. - Paris, as a matter of fact, radiates 1 air beacons in all directions. In addition to the London to Paris route, beacons stretch in. a. north-easterly direction through Belgium and Holland to Copenhagen in Denmark. Due east the light pilot looking dow n foi 1 those important pin-points of light, is guided to far-off Strasburg oil the borders of Germany. Southwards, these street lamps of the air reach down to tlie warm shores of the MediI terranean as far as Nice. I In the United States there are thousands of miles of carefully lighted air routes. . It was soon realised that much of.the advantage of high speed would he lost if aeroplanes lay idle all pieht.

From New York to Rock Springs, to take only one instance, there are strings of 500,000,000 candle-power

beacons every ‘2O or 30 miles. .Smaller automatic acetylene beacons are placed every three or four miles at temporary landing sites in case ot trouble. But the most powerful beacons in America arc feeble indeed compared to a monster at Dijon in the centre ol France, reputed to be the most powerful in the world. This aerial lighthouse. with its billion candle-power light, is designed to furnish a night landmark throughout practically the whole ol France. On a clear night its revolving beam can lie seen at a distance of 240 miles, roughly from the Mediterranean to the'English Channel, and eastwards into Switzerland, Italy, Austria and Germany. The actual lighthouse, some 40 feet high, stands on an elevation known, as Mont Alrique, nearly 2000 feet high. The entire projection apparatus is a marvel of ingenuity being controlled entirely from a room below. So far, no really satisfactory system lias been discovered for lighting aerodromes, once the beacons have guided tho pilot to his destination, but fairly successful experiments have been carried out at Croydon with neon lamps. It has been discovered that these lamps can be seen further by night, particularly in mi’sty weather, than any other known source of light. Line's of these neon lights, wide enough apart for an air liner to alight between them, afe installed in concrete troughs sunk level with the aerodrome and covered with thick glass. Pilots describe these brilliant lines of red lights as appearing from the air like lanes ol lire iilainly marking the landing area without dazzle.