Tyndall, John, 1820-1893 · London : Longmans, Green · leaf 443
m the mirror of the horizontal to thatof the vertical fork, and from the latter to the screen, on BE 2 420 LECTURE IX. which it prints a brilliant disc. I now agitate the up-right fork, leaving the other motionless. The disc isdrawn out into a fine luminous band, 3 feet long. Onsounding the second… … have caused a beam of light to vibrate simultaneously intwo directions, and have accidentally hit upon the phasewhen one fork has just reached the limit of its swing, andcome momentarily to rest, while the beam is receivingthe maximum impulse from the other fork. That the circle was obtained is, as…
Sound
Internet Archive · Boston Library Consortium · Public Domain Mark 1.0. Free to use for anything.
