ANALEMMA, denotes likewise an instrument of brass or wood, upon which this kind of projection is drawn, with a horizon or cursor fitted to it, wherein the solstitial colure, and all circles parallel to it, will be concentric circles; all circles oblique to the eye will be ellipses; and all circles whose planes pass through the eye, will be right lines. The use of this instrument is to show the common astronomical problems: which it will do, though not very exactly, unless it be very large.