細節
A cased set of instruments for magnetic experiments,
19th Century
including a brass-cased gimballed compass, four magnetic bars, a compass needle, six steel balls, a brass cylinder shaker, two spindels, four brass roundels with needles, an ivory tapered tube, and graduated arc on base with pillars to bridge with steel strip, and other items, in fitted mahogany case
23.4 x 4.8 x 13.2cm. (9¼ x 1 7/8 x 5¼in.)