CASTS NO SHADOW

Rotorua Morning Post, Volume 2, Issue 445, 1 February 1933, Page 2

CASTS NO SHADOW

NEW LIGHT UNIT VALUABLE DISCOVERY WILL ASSIST HOSPITAL - WORK. . . ; NEW ZEALANDER'S INVENTION. It casts no shadow! That is the interesting feature of the new lighting unit devised hy 'a Brisbane engineer, who hopes that some day his invention will be in use in every hospital in Australia where there is an opeyating! theatre, and for many other purposes besides. He. has. combined indirect . and diffused- Mghting-to such happy effect that no mattey how he works the pperator, cannoti "stand in his own'light." That there is no shadow from the light is the, imp'ortant feature from the point of view of hospital work, for the surgeon is enahled. to . operate' a few inches from the lamp without the shadow of his hands or instruments interefering with his vision of the delicate work he is performing. There are a number of surgical lights of this kind, but th'e inventor claims that only in -the case -of his- lamp is the light available not only for a circumscribed area on the operating table but for the illumlination of the; rest of the theatre as well. Not Experimental. "It is not experimental," he says. "An earlier model than this one has been in operation in the Lismore District Hospital, and is giving excellent service, although.it has not the perfections which I have added to the lamp I have here. now- The beauty of . this lighting- unit is that no matter how strong. the actual electric .bulb, there is no. glure from the lamp, and ypu may look right into it without the slightest .discomfort. "The' illumination is not confined to a small circle immediately below the lamp, but is diffused all over the roofn. Other shadowless lamps, ypu wiR find, throw. a, brilliant shadpwless light within that. small cipcle,.but outside it all is pitch darkness. With this, there is.sufficient light for all in. the operating- theatre — sisters, students, assistants — all to see to work and move about. . ■ "Again, there is the matter of glare. One1 surgeon in Sydney.-of whom I have heard, insists that only -blue sheets and fittings ish'all be used under- the operating lamps. The reason ds tbat after working for hours under the glare, the eyes are affected, and a form of mild snow-blindness is-caus-ed by the reflection from the white sheets. There is no glare from this lamp, The Wrong Idea. "People have the wrong idea about light," he continued. "They think that Rght to be of high intensity must he direct. That is all wrong. Glare is ruinous to the eyes. Have intense light by all means, but let it be diffused. You get just as much light, and no ill effect on the sight. • This is the first time that both indirect and diffused "light • have been so'mbined for this purpose, and you see the result." The result was that the interviewer was able to gaze directly into the light without even blinking his eyes. The smallest print was plain and clear, and— interesting this— 7-colour values appeared to be unimpaired hy the artificial light. To look at the "Wickham Electric" lighting unit, as th'e inventor' and patpntee (Mr. R. M. Knowles) has called it, faintly resemblessan inverted wash-hasin. The 28-inch ho.wl was beaten out in Brisbane, and all the parts (with the exception of the 300 candle-power light bulb itself) were also made in the city. ■ The inside of the howl, which hangs hy four cahles, has a white matte surface, and in the centre is a new type of "obturator'1'— a metal disc with a protruding. centre, making in all a shape like a somewhat flattened military "tin hat" of shining chrominm plate. Round the edge of the bowl is a "bus bar" handle, with which the apP'aratus is raised or lowered or set to any desired angle from vertical to horizontal. By means .of a. douhle cpunterweight, jone Weight working within the other, the lamp stays "put" at any desired angle, its "motility" being thus practically perfect.. By a touch -of the hand it moves up or down, -and remains at any angle until touched again. . The "Obturator." The white bowl interior diffuses the light from the electric bulb, while the plpturator, or metal disc, prevents any direct light from reaching the ohject tq be illuminated. Hence the light is dpdirect' as well as diffused, 'and is not confined to a circumscrihed area. There is, too, a focussing device of -a simple nature. . . ' ! There is apparently no reason wh it cannot he madeTn Brisbane at once for distribution throughout Australia, e^cept for the one difficulty— the- spinning of the 28-inch bowl, which would rpquire a- special plant. A purface.pf vitreous enamel, which is untarnishahle and imperviops to acid, gas and heat, will prcfxably he. substituted for the present surface. . All the "ingredients" can he made in Australia, and indeed in Brisbane, so it is to he h'oped that the manufacture of the apparatus. will. be , secured for Queenslqnd, . Although there are, as stated, spveral -, shadowless lamps ;manufaqtured in various part of the world, the inventor claims that,. the, only pth.er light of equal efficiency costs more than twice as much to ohtain. Adaptations of the Wickham Electric -are suitable, h'e. helieves, forTabpratory work,. photographic studiqs (one has actually been ordered for this purpose in' Brisbane), linotype and sewing machines, . tailor shops, lathes, drilling piachines, ! draw'ing and drafting offices, lithographers and engravers, jewellers and dry 'cleaning shops, ship'S. holds and engine rooms, machine sh'ops -and dental sfirgeries, . Born in New Zealand and trained in engineering in the United States of America," the - inventor* is Mr. R. M. Knowles, of Wickham Terrace. He has been resident ip Brisbane for two years. Experiments on the lamp have been in progress for 10 months, and the patent was granted on June 2 last. ■ The company hopes that operations will reach the -manufacturing stage sh'Ortly, and negotiations are already in progress, with ,-this obiect.in