[ CXL]
A Step Ladder at an Angle
First draw the ground-plan G at the required angle, using vanishing and measuring points. Find the height hH, and width at top HH·, and draw the sides HA and H·E. Note that AE is wider than HH·, and also that the back legs are not at the same angle as the front ones, and that they overlap them. From E raise vertical EF, and divide into as many parts as you require rounds to the ladder. From these divisions draw lines 1 1, 2 2, &c., towards the other vanishing point (not in the picture), but
having obtained their direction from the ground-plan in perspective at line Ee, you may set up a second vertical ef at any point on Ee and divide it into the same number of parts, which will be in proportion to those on EF, and you will obtain the same result by drawing lines from the divisions on EF to those on ef as in drawing them to the vanishing point.
Fig. 252.