Quadrantal Deviation. Compass error arising from induced magnetism in horizontal soft iron. Changes name, E or W, in successive quadrants.
Quadrantal Triangle. Spherical triangle having one side of 90°.
Quadrant Davit. Boat davit whose head can be moved through 90° in vertical plane; Welin type being, perhaps, the best known.
Quadrantids. Meteor shower visible in northern sky at beginning of January; radiant point being in constellation Quadrans Muralis.
Quadrate. Said of two heavenly bodies when 90° apart.
Quadrature. Relative position of a heavenly body when 90° from another. 2. Position of Moon when she is halfway between conjunction and opposition, thus being quadrate with Sun.
Quadrireme. Roman vessel, possibly with four banks of oars. Greek equivalent 'Tetreres'.
Share with your friends: |
