EQUULEUS

, Equiculus, and Equus Minor, Equi sectio, the Horse's Head, one of the 48 old constellations, in the northern hemisphere. Its stars, in Ptolomy's catalogue, are 4, in Tycho's 4, in Hevelius's 6, and in Flamsteed's 10.

ERECT Vision. See Vision.

Erect Dials, such as stand perpendicular to the horizon, and are of various kinds; as Erect Direct, when they face exactly one of the four cardinal points, east, west, north, south; and Erect Declining, when declined from the cardinal points. See Dial.

To Erect a Perpendicular, is a popular problem in practical geometry, and denotes to raise a perpendicular from a given line &c, as distinguished from Demitting or letting a perpendicular fall upon a line &c, from some point out of it. See Perpendicular.