Laurence, Lionel · London, School of Optics · leaf 122
nds with the trigonometrical division of the circleinto 360 degrees. The uppet right quadrant contains the angles between 0°and 90°, and the upper left those between 90° and 180°. The notation isnot carried beyond 180° (the half-circle), since a meridian corresponds toa diameter, i.e. to two… … 90 iQj i?o m/osoh m^^ Fio. 117a.
Optics
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