agonic line

noun

1. an imaginary line on the surface of the earth connecting all points at which the declination of the magnetic field of the earth is zero.

agonic line

noun

1. an imaginary line on the surface of the earth connecting points of zero magnetic declination

agonic line

/ ā-gŏn′ĭk /

1. An imaginary line on the Earth's surface connecting points where the magnetic declination is zero. The agonic line is a line of longitude on which a compass will show true north, since where magnetic declination is zero, magnetic north coincides with geographic north.

Word History and Origins

Origin of agonic line¹

First recorded in 1860–65

Example Sentences

To the east of the agonic line the declination is westerly, and to the west it is easterly.

From Project Gutenberg

At present the motion of the agonic line seems to be towards the west, but it is very slow.

From Project Gutenberg

The line passing through points where the needle points north, without declination, is the agonic line.

From Project Gutenberg

Agonic line, line along which the needle points due north and south.

From Project Gutenberg