"A magnet which owes its magnetic properties to the inductive action of an electric current." -Whitney, 1911

Electromagnet

"A magnet which owes its magnetic properties to the inductive action of an electric current." -Whitney,…

"Astatic galvanometer, an instrument which consists of a pair of similar needles magnetized, with their poles turned opposite ways, and stiffly connected at their centers, so that both will swing together." -Whitney, 1911

Astatic Galvanometer

"Astatic galvanometer, an instrument which consists of a pair of similar needles magnetized, with their…

A bar or mass of steel or iron to which the peculiar properties of the loadstone have been imparted, either by contact or by other means.

Magnet

A bar or mass of steel or iron to which the peculiar properties of the loadstone have been imparted,…

If a magnetized bar or needle be suspended at its centre of gravity so as to move freely in a horizontal plane, after a few oscillations it will come to rest, with one of it ends pointing nearly to the geographical north pole of the earth.

The Magnetic Needle

If a magnetized bar or needle be suspended at its centre of gravity so as to move freely in a horizontal…