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 111
by the in-fluence of the earth. If,now, the extremities ofthe wire are put in con-nection with the poles of a galvanic battery, in sucha manner as to cause a current of electricity to passthrough it, the needle, N S, will be deflected, andwill turn towards the position a b or c d, accordingto the… … DEFLECTION OF NEEDLE. 95 the same current when flowing above. If the posi-tive current is passing from south to north in thewire, as shown by the arrow in the cut, the northpole of the needle will turn to the west if it bebelow the wire, and to the east if above it. 150. In these cases, the needle…
