Tyndall, John, 1820-1893 · New York : Appleton · leaf 52
on its stand to make the image ofthe flame fall upon any one of the row of persons who occupythe front seat in the gallery. Removing the candle, andputting the watch, w, Fig. 8, in its place, the person onwhom the light fell distinctly hears the sound. Whenthe ear is assisted by the glass funnel,… … One of these two parabolic mirrors, n n, Fig. 9, is placedupon the table, the other, m m, being drawn up to theceiling of this theatre ; they are five-and-twenty feet apart.When the carbon-points of the electric light are placed inthe focus a of the lower mirror and ignited, a fine lumi-nous…
Sound
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
