Photo by David Friend Productions, San Diego, California
'GRIGG'S CONICAL ELECTROMAGNETIC MACHINE'
15-019. English, "Patented Jany 8th, 1873," and signed on a sliver plate atop the coil "Grigg's Conical Electro Magnetic Machine, 31 Westbourne Terrace Hyde Park, LONDON, Maker Chislett Plymouth." Made of mahogany with polished lacquered brass fittings and standing 4" high overall on its 10 3/4" x 4 1/2" mahogany base. The 9 5/8" long x 2 7/8" diameter (max) conical mahogany coil housing tapers down to 1 3/4" diameter (min), with an adjustable 1/2" diameter ivory capped soft iron wire core inserted in the small end. An electromagnetic interrupter and the lacquered brass battery connectors are mounted on one side of the coil base; the coil output connectors are mounted on the other side. This rare early medical induction coil is in fine display (and probably still completely functional) condition.
