Wright, Mark R., 1854- · London : Longmans · leaf 80
he second mirror, are again reflected to itsfocus. This is the better demonstrated by substituting the tapsfor the ticks of the watch, and the sensitive flame for the ear. Whispering-galleries.—We can easily understand that if agallery be of a certain shape, the whisper of a person in onepart may… … Fig. 54. is, that the waves of sound reflected are from the interior andare thus prevented from spreading. Instead of the intensity 72 Sound being inversely as the square of the distance, there is but aslight diminution of sound. Reduce the sensitive flame until it is not affected by the…
Physics
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