AXIS n.
cts a system of parallel chords of a curve; called a principal axis, when cutting them at right angles, in which case it divides the curve into two symmetrical portions, as in the parabola, which has one such axis, the ellipse, which has two, or the circle, which has an infinite number. The two axes of the ellipse are…
BALLAST n.
Fig.: That which gives, or helps to maintain, uprightness, steadiness, and security. It [piety] is the right ballast of prosperity. Barrow. Ballast engine, a steam engine used in excavating and for digging and raising stones and gravel for ballast. -- Ship in ballast, a ship carring only ballast.