Light; a course of experimental optics, chiefly with the lantern . prepared to expect colour if the film is thinenough to allow the two to act upon each other at can subject the matter to experiment in many ways, allof which give phenomena of great beauty. Take a small black tray or hand-waiter w, say 8 by 12inches, lay it on the table, or on a block to raise it if need-ful, and fill it half an inch or so deep with water. If it is alime-light, cant up the back of the lantern, as in Fig. 94, sothat the parallel (or rather slightly divergent) beam from theflange-nozzle with the objective
Light; a course of experimental optics, chiefly with the lantern . prepared to expect colour if the film is thinenough to allow the two to act upon each other at can subject the matter to experiment in many ways, allof which give phenomena of great beauty. Take a small black tray or hand-waiter w, say 8 by 12inches, lay it on the table, or on a block to raise it if need-ful, and fill it half an inch or so deep with water. If it is alime-light, cant up the back of the lantern, as in Fig. 94, sothat the parallel (or rather slightly divergent) beam from theflange-nozzle with the objective removed may fall on thewater at w, and be reflected to the screen s. If it is a gas-burner, the reflector must be used to bring the beam down;and in sorne situations it will be best to focus the surface on i6o LIGHT: [chap. the ceiling, as in some previous experiments; but with thelime-light the plain beam is,best. Having adjusted all, flipthe end of a pen-holder or any pointed rod into a bottleiofspirits of turpentine, and let a single drop fall on the Fig. 94.—Film of Turpentine. It spreads out instantly, and the reflected light on theceiling or screen is tinged with the most beautiful a polished steel plate 3 or 4 inches square on asmall tripod, and place a spirit-lamp or Bunsen flame under-
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Keywords: ., bookcentury1800, bookdecade1880, bookidcu3192403121, bookyear1882
