An elementary book on electricity and magnetism and their applications (1919)
Jackson, Dugald C. (Dugald Caleb), 1865-1951, Jackson, John Price, b. 1868, Black, Newton Henry, b. 1874 · New York, The Macmillian Co · leaf 105
ells and holding itabove the needle (Fig. 39) while thecurrent flows through the wire. Theeffect on the needle may be made mostevident by making and breaking theelectric circuit. The needle will swingback and forth, since it will be deflectedevery time t he circuit is closed and willreturn toward… … Fig. 39. - Wire held above mag-netic needle. ELECTROMAGNETISM 85 north and south direction — that is, when the wire is parallel with theneedle. The earth itself is a great magnet, and it is the force of theearths magnetism that causes the needle to turn into a northand south position and stay there…
Electricity · Magnetism
Internet Archive · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer01inte-95-21.webp)
