Light; a course of experimental optics, chiefly with the lantern . Fig. 36. 32. Total Reflection.—But there is a curious limit tothis. Seeing that as the angle of incidence increases, the re-fracted ray is more and more bent downwards, or towards theperpendicular, we cover the top of the tank with a bit of plainboard, and place the metal strip upright against the end ofthe tank, in the position of Fig. 37. Gently canting ourlantern a little, we pass the beam direct through the slit e(Fig. 37), so as to enter the water almost horizontally. Wefind the ray bent down a great deal, about at an angl
Light; a course of experimental optics, chiefly with the lantern . Fig. 36. 32. Total Reflection.—But there is a curious limit tothis. Seeing that as the angle of incidence increases, the re-fracted ray is more and more bent downwards, or towards theperpendicular, we cover the top of the tank with a bit of plainboard, and place the metal strip upright against the end ofthe tank, in the position of Fig. 37. Gently canting ourlantern a little, we pass the beam direct through the slit e(Fig. 37), so as to enter the water almost horizontally. Wefind the ray bent down a great deal, about at an angle of45°, as shown by the thin white line c d. Now we haveascertained that if we throw the ray first by our reflector 54 LIGHT. [CHApi. up through the water, in this case the path is exactly re-versed. It occurs to us at once, that if we sent our beam at a slightly greater angle (neverforget that all angles measurefrom the normal) through thewater, there is no path in theair it can assume : it would ap-pear that it could not get outof the water at all., -We tr
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Keywords: ., bookcentury1800, bookdecade1880, bookidcu3192403121, bookyear1882
