NOCTOVISION WONDERS.

Otago Daily Times, Issue 20252, 10 November 1927, Page 13

NOCTOVISION WONDERS.

PRINCESS MARY AND A TEST. MR J. L. BAIRD’S EXPERIMENTS. (Fbou Qua Own Correspondent, j LONDON, September 14. Apart from the somewhat bewildering embarrassment in the close-on-400-papers which are to be read at the British Association meeting at Leeds, this year’s assembly promises to be marked, by other intensely interesting features.. Take, for instance, the television and noctovision experiments which are to be carried out by Mr J. L. Baird. It- is understood by the Leeds correspondent of the Daily Telegraph that possibly princess Mary Viscountess Lascelles will participate in one of the experiments. Her Royal Highness is expected to visit the exhibition of scientific instruments connected with the association meeting, and it is hoped that she and Viscount Las-celies-will take part in a demonstration of noctovision—that is, television using infra red rays instead of ordinary light for illumination—to be given in the Education Department buildings. The Princess will be seated in a dark room, and, by means of Mr Baird's perfected wonder-working noctovision apparatus, her features will be revealed on a screen in an adjoining room to Viscount Lascelles. It is hoped, further, to transmit the Princess's picture from. the same Leeds room to the headquarters of the Baird Television Company in London. A series of television and noctovision demonstrations between London and Leeds will be made another day, members of the British Association taking part in them at this end. For the transmission of faces from the metropolis wireless may be utilised, otherwise trunk telephone wires, while from Leeds to London reliance* will be on trunk telephone wires. It may be recalled that by using, in place of light, infra red rays in conjunction with a modified form of television receiver and transmittter, Mr Baird was able at the end of last year to demonstrate vision in total darkness to members ’of the Royal Institute. On that occasion persons seated in a totally dark room were seen and recognised by friends on a screen in a different apartment, all movements being faithfully portrayed. Apart from demonstrations of television, which may be briefly defined as transmission of vision by electricity, and demonstrations of noctovision —vision produced in darkness by means of infra red rays—there are to be revealed the uncanny powers of the phonovisor. an apparatus by which moving images can be recorded on and reproduced from a photograph record in the same manner as sound. Ip the transmission of an object or scene by television, the image or scene is first transformed into a fluctuating electric current. This current may be heard in the telephone as a sound ; 'every face or scene having its corresponding sound. The lights and shades of different faces cause different sounds, and it is even possible to distinguish one face from another by these differing sounds or “notes,” which can be permanently recorded on a phonograph record. Then, to complete the magic process, if this record is played into a televisor, the original moving scene which caused the sound is reproduced on the screen of the, televisor. Mr Baird has recently devoted much time arid study to the effort to evolve perfection of the phonovisor, and the result of the coming demonstrations with this apparatus is being eagerlyawaited by devotees of applied science.