Drawing Foreshortened Circles : How to Draw Circles at Angles ... Which Then Look Like Ellipses / Ovals

Drawing a Circle When Turning it Left or Right, or Tipping it Forwards or Backwards

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The Circular Tablet, Cylinder and Cone

By the same method of measuring with the pencil at a fixed distance from the eye, notice

1. That, when a circular tablet is held directly in front, the horizontal and vertical diameters appear the same length. The tablet appears as it really is—a circle. (Fig. 160.)

2. That, if the position is changed by turning it to the right or left, the horizontal diameter is foreshortened while the vertical diameter appears as before. In this position it may be represented by an ellipse which becomes narrower the farther the tablet is turned from the original position, finally becoming a vertical straight line. (Fig. 161.)

3. That, if the position is again change by tipping the top backward and the bottom forward, the vertical diameter is foreshortened and the horizontal diameter appears as before. It may be represented, when in this position, by an ellipse which becomes narrower as the tablet is tipped farther from the original position, finally becoming a horizontal straight line.

4. That, if it is held in a horizontal position on a level with the eye (A), it appears a horizontal straight line ; but if lowered or raised (B), the receding diameter is foreshortened. It may then be represented by an ellipse which becomes wider as the distance above or below the eye level is increased. (Fig. 163.)

5. That, if held vertically with edge pointing towards the eye, it appears as a vertical straight line (A); but if moved to the right or left (B) it appears as an ellipse which becomes wider as the distance to the right or left is increased.

Problems.

1. Draw the circular tablet in an oblique position, the horizontal diameter receding.
2. Place the tablet in an oblique position ; both diameters oblique. Draw the ellipse by which it may be represented and indicate the diameters. A tablet about IR in. in diameter is the best for class use. It should be made of light colored pasteboard and held In front of a dark background. Vertical and horizontal diameters should be plainly drawn in black.
3. Draw the circular tablet as it appears when lying on the desk in front ; both diameters receding.
4. Place the circular tablet in a slanting position ; one diameter horizontal, the other receding upward from the ground. Draw the ellipse by which it is represented and indicate the diameters.
5. Draw a group of three circular tablets each in a different position.