The Civil engineer and architect's journal, scientific and railway gazette (1839)
London : [William Laxton] · leaf 229
e two light w ire frames, F Ftwo helices, // a Ritchies rotatingmagnet; on the tops of the wire framesand helices are small cups to containa drop of mercury, G is a piece ofbrass wire bent twice at right anglesand terminated at each end by a finepoint to dip into the globules of mer-cury : it can… … ming noise and sometimes a loud musical sound is excited by the rapid vibra-tory motion assumed by the fixed magnet during the rapid revolution of theelectro-magnet. This musical sound is best observed when the levellingscrews of the tripod are placed on a mahogany table in the middle of a…
Architecture · Civil engineering · Science
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