Practical plane and solid geometry for advanced students, including graphic statics, adapted to the requirements of the South Kensington syllabus (1899)
Harrison, Joseph, Baxandall, George Albert · London Macmillan · leaf 402
out a vertical axisthrough O. The points Av Av where this elevation cutsthe elevation of the sphere, give the highest and lowestlevels for the section planes. The two sections at theselevels give the two points A, A; at a, a the requiredcurve is horizontal; at a, a the tangents are parallel to mn.… … this section gives the two points B, B on the curve, whoseplans b, b are on the outline plan of the sphere. Observethat the plan of the curve touches the outline at the pointsb, b where the two meet; note also that the points b, bseparate the full and dotted parts of the curve, which repre-sent the…
