Appleton's cyclopædia of drawing, designed as a textbook for the mechanic, architect, engineer, and surveyor (1866)
Worthen, William Ezra, 1819-1897, [from old catalog] ed, Appleton, firm, publishers, New York. (1866. D. Appleton & co.) [from old catalog] · New York, D. Appleton and company · leaf 94
II let fall a perpendicular on tlie axis ^i h / ex-tend the axis to the left of A; make A a equal to A 5 / draw a II, andit is the tangent required. The lines perpendicular to the tangent are called normals. To findthe normal to any point I, having the tangent to any other point II.—Drawthe normal… … 74 GEOMETKICAL PROBLEMS. The Hyperbola. An hyperlola is a curve from any point P in which, if two straightlines be drawn to two fixed points, F F the foci, their difference shallalways be the same. Peob. LXY.—To describe an hyperbola (fig. 168). From one of the foci F, with an assumed radius,…
