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"Salient pole, bipolar field magnet with single coil wound around the yoke." — Hawkins, 1917

Bipolar field magnet

"Salient pole, bipolar field magnet with single coil wound around the yoke." — Hawkins, 1917

In field fortification, the simplest kind of work employed, consisting of two parapets of earth raised so as to form a salient angle, with the apex towards the enemy and unprotected on the rear. Several redans connected by curtains form lines of intrenchment.

Redans

In field fortification, the simplest kind of work employed, consisting of two parapets of earth raised…