UNSEEN SEARCHLIGHT.

Waikato Times, Volume 102, Issue 17015, 31 January 1927, Page 5

UNSEEN SEARCHLIGHT.

—•—<► TELEVISION DISCOVERY. EFFECT ON FUTURE WARFARE. A Special Correspondent writes in the London Daily Mail — Accompanied by a colleague I was permitted lo take part in a first demonstration —apart from secret tests before naval, military, and Air Force officials —of seeing in total darkness by means of an invisible ray. Mr John L. Baird, inventor of the Baird “televisor,” who gave the first demonstration of television on January 27 this year, is the producer of ibis invisible ray, and describes as follows the experiments leading to its application:— “In my first demonstrations of television it was necessary for the person being ‘transmitted’ fo sit before an intensely J might light. Its intensity was so great, in fact, as almost to blind the sitter. Before, therefore, my ‘televisor’ couhl he feasible commercially if was essential that this enormously brilliant light should he dispensed with. “For six months I have been concentrating upon reducing the brilliance of the lighting, and with such success that it is now possible by my ‘televisor’ to see a person who is sitl.ing some distance away in total darkness. This is accomplished by isolating, and then employing, rays which are outside the visible spectrum. The human eye cannot see them, but the sensitive ‘electric eye’ of niv apparatus detects them readily.

Raya Sent by Wireless

Tn the demonstrations my colleague sat in darkness before the transmitting screen of the “televisor.” Above his head, shut off by an enclosed space from the room, were a certain number of ordinary electric lights. The rays from these impinged upon a light filter. This filter extracted everything that was visible from those rays, and only allowed to pass into the room certain rays in Ihe lower invisible to the human eye,. gU;se unseen rays bathed my eolleagi’n ‘s head and shoulders, without Ids'being in Ihe least conscious of the fact, and a Tier they had been “analysed” by an apparatus in front of Ihe Iransmillrr were fashed by wireless across an intervening empty room to the sensitive cell of Mr Baird's “televisor.” Tins was installed in a third room: il had been adapted specially to rays and lo project them in „ .isible form upon a screen. In the receiving room 1 sat in total darkness before the small screen, us

1 it flickered and then clarified an easily j recognisable bead and shoulders of my ! colleague as he sat in the other room !in pitch-black dark, lie turned his j head, as we bad agreed lie should, I opened and shut his eyes, and drew j back and then approached nearer, j The fidelity of the image was perfect. | I was accomplishing the apparent ! miracle of seeing a distant person in j the dark who was illuminated by a ray j invisible to the human eye. j This ability to “see” by means of j rays unseen by those upon whom they I are turned opens up astonishing possi- ! hilities.

! “It is difficult,” said Captain 0. 0. : Hutchinson, who is associated with Mr ! Baird, “to estimate what may be the | importance in war of this invention. !It becomes feasible to follow an j enemy’s movements when lie believes himself to be in darkness. Attacking aeroplanes approaching under cover of night will be disclosed to the defending headquarters by the electric eye of the ‘televisor.’ They will he followed by searchlights emitting invisible rays, and as these rays will he unseen by them they will continue to approach until, without warning, they are brought down by the guns of the defence. “Darkness, that cloak of military operations, will give security no longer. Creeping forward for a surprise assault in pitch blackness an attacking party will he swept by an invisible ray and watched on the ‘televisor’ screen of the defenders. The attackers will be allowed to come well within range and will then find themselves, in spite of the apparent darkness, overwhelmed by gunfire.” Fog Penetration. The invisible ray, Mr Baird explained, could he focussed and Hashed through lenses like an ordinary searchlight, hut owing to its nature it would be more penetrative and could he thrown ‘further than any visible ray. For naval, military, or flying purposes it would he used in conjunction / with a special receiving screen or I “eye,” upon which would he focussed t an image of any distant object upon which the invisible searchlight was turned. The nature of the rays would also enable them to penetrate fog more readily than any other form of ray, and in this respect they might have great significance commercially in the operation during foggy w'catlier of ships, trains, and aeroplanes.