A text book of geometrical drawing, for the use of mechanics and schools, in which the definitions and rules of geometry are familiarly explained (1849)
ix of the parabola.2nd. The axis is the line /. Hy passing through the focus^ and perpendicular to the base C. D,3rd. The principal vertex^ is the point Jy where the top of the axis meets the curve.4th. The parameter^ is a hne passing through the focus^ parallel to the base^ terminated at each end…
