analamma

[In Ger. & Lat. analemma. From Gr. ἀνάλημμα ( analēmmma ) = that which is used for repairing or supporting anything; ἀναλαμβάνω ( an a lamb anō ) = to take up: ἀνά ( ana ) = up, and λαμβάνω ( lamb anō ) = to take.] 1. Geom.: A projection of the sphere on the plane of the meridian orthographically made by a straight line and ellipses, the eye being supposed at an infinite distance, and in the east or west point of the horizon. IMG:content-0491.png:[blocks in formation] 2. Mech. An instrument made of bra or wood on which the projection now mentioned is drawn, with an horizon or cursor fitted to it, in which the solstitial colure and all circles parallel to it will be represented as concentric, all circles oblique to the eye as ellipses, and all the planes of which pa through the eye as straight lines. The analemma now described is used for illustrating, at least with an approach to accuracy, the various astronomical problems.