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 192
r is made to rotate by transmitting the bat-tery current through either half. This mode ofsuspending the rotating bar was first suggested byDr. Boynton, The screw-cup A, on the stand, con-nects with the brass pillar, and thence with one endof the coil. The other end of the coil dips into mer-ciuy,… … 176 DAVISS M ANU A I* jecting from the middle of the bar, conveys the cur-rent from the mercury through its upper half to the„. -jg cup B. Some non- conductor of electrici-ty, interposed at I, in-sulates B from the armwhich supports it. IfA and B are connect-ed wilh the battery^and the cistern…
