POLAR JUBILEE.

Press, Volume LXVIII, Issue 20510, 1 April 1932, Page 11

POLAR JUBILEE.

RING OF OUTPOSTS. TWO BRITISH EXPEDITIONS. (UKITED TRESS ASSOCIATION—BY ELECTBIC TELEGHAi'U—COPYRIGHT.) LONDON, March 30. Tlio jubilee of tlio first international Polar expedition will be celebrated this year. Many of the original participants, including Great Britain, Canada, France, America, Holland, Sweden, and Itussia, are organising a ring of observation posts about the North Polo, and maintaining them for several months to make meteorological, electrical, and auroral observations. Ono possible result Avill be moro accurate weather forecasts. Great Britain is organising two expeditions, one to Tomsce, under the leadership of Professor Appleton, ana tho other to Fort Rao, in Northern Canada, where a British expedition wont in 1882, and which is ono of tho coldest places on earth, it being even colder than tho North Polo. Both expeditions are giving attention to tho Heaviside layer theory. Mr J. M. Stagg, leader of the Fort llao party, says he will especially investigate tho supposition thnt tho Aurora Borealis is supported GO miles abovo the earth by tho Heaviside layer. They will attempt to establish tho •height of tlio Aurora by simultaneous photographs taken 2-5 miles apart. The Heaviside layer is called after the discoverer of the remarkable property of tho upper layer of the atmosphere as affecting radio transmission. Heaviside originated the th6ory and demonstrated it, and now it is generally accepted. His theory is that tho upper layer of tho air is ionised by light radiation from the sun, and that this condition prevents tho passage through this upper air of radio waves, except the ultra short waves. It also acts as a reflector of all ordinary transmissions, causing the impulses to strike downwards back to earth at tho corresponding angle, in the same way as a mirror gives back light rays. The layer is ofton of uneven surfaco, and of uneven density, so that tho reflection from it varies in different places and at different times. It is believed that the 1 patchy reception of radio messages is duo, at least in part, to the reflecting action, often uneven, of tho Heaviside layer.