"COLURES, in astronomy and geography, are two great circles supposed to intersect each other at right angles in the poles of the world, and to pass through the solstitial and equinoctial points of the ecliptic.
"That which passes through the two equinoctial points, is called the equinoctial colure, and determines the equinoxes; and the other which passes through the poles of the ecliptic is called the solstitial colure, because it determines the solstices. By thus dividing the ecliptic into four equal parts, they mark the four seasons, or quarters of the year." —Falconer's New Universal Dictionary of the Marine (1816), 95
"COLURES, in astronomy and geography, are two great circles supposed to intersect each other at right angles in the poles of the world, and to pass through the solstitial and equinoctial points of the ecliptic.
"That which passes through the two equinoctial points, is called the equinoctial colure, and determines the equinoxes; and the other which passes through the poles of the ecliptic is called the solstitial colure, because it determines the solstices. By thus dividing the ecliptic into four equal parts, they mark the four seasons, or quarters of the year."
—Falconer's New Universal Dictionary of the Marine (1816), 95