Letters on natural magic, addressed to Sir Walter Scott, bart (1834)
Brewster, David, 1781-1868. n 84239125 · London : J. Murray · leaf 207
quare plate of glass A B, ground smooth at its edges, is pinched by the finger and. thumb. In No. 2, a circular plate is held by the thumb against the top c of a perpendicular rod, and damped by the fingers at two diflerent points of its circumference. In No. 3 it is damped at three points of its… … If we take a square plate of glass, such as that shown in Fig. 46, No. 1, and, pinching it at its centre, draw the fiddle-bow near one of its angles, the sand mil accumulate in the form of a cross, as
Scientific recreations
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