Davis's manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity (1854)
Davis, Daniel · Boston : Palmer and Hall · leaf 162
MAGNET AND ROLLER. 145 … 230. Magnet and Roller. — Some of the phe-iiomena of magnetic attraction and repulsion may ^. ^„ be shown by the ar- Fig, 93. ^ rangement represented in Fig. 93, The polesof the steel magnet, NS, are raised by a littlewooden block, and apiece of iron, A, .s placed across, near the bend. Ashort iron…
