Page:An introduction to linear drawing.djvu/86

67 ﻿the point of view V, draw the two lines E V and U V and the point where these two lines are cut at T by the line X 3 raise a second perpendicular till it strikes P on the line E V. On the tops of the perpendiculars X Y and 3,2 finish the dotted arch passing through the point P and you have the perspective width, height, fcc. of the first arch.

What is meant by Perspective Drawing? What is meant by the Perspective Plane?
 * 1) On what does the apparent size of an object depend?
 * 2) Is the angle increased or diminished by the distance of the object ?
 * 3) When does an object become invisible?
 * 4) What is meant by the Vanishing Point?
 * 5) What is meant by the Point of Sight?
 * 1) What are Visual Rays?
 * 2) What is the Horizontal Line?
 * 3) What is meant by the Centre of the Picture?
 * 4) What is the Prime Vertical Line?
 * 5) What are the Points of Distance?
 * 6) What is the Ground Plane?
 * 7) What is the Base Line?

The teacher should now take figure third and ask the name of each line upon it. He should also require each pupil to draw a similar figure, but not of the same dimensions. If the figure be drawn with chalk on a black board before the class, it will be easy to require each pupil to draw a portion of the figure to show that he