The height of a cylinder is the length of the axis, or the distance from one base to the other. If the axis be perpendicular, the cylinder is upright.

Here, as in the cone, the laws of perspective change the circles into ellipses. The axes of the ellipses, and that of the cylinder, may be given in inches by the monitor.

(11)

(12)

19. Draw an upright cylinder. (fig. 12.)

20. Cut a cylinder by a section parallel to its base. (figs. 11 and 12.)

21. Make a cylinder whose axis shall be horizontal. (fig. 13.)

(13)

FIFTH CLASS.

THE figures of the Fifth Class are formed by the union of such lines as have already been given, viz. horizontals, perpendiculars, and arcs of circles or ellipses.

1. Draw a fillet. (fig. 1.)

2. Draw a bead. (fig. 2.)

3. Draw a congee. (fig. 3.)

(1)

(2)

(3)

These mouldings, as they are called in architecture, are so simple as to need no explanation. Horizontals and verticals will be found in them, with circles, of which the dotted lines mark the centre.

4. Draw a torus with its plinth. (fig. 4.)

(5)

The torus, of which the profile is here given, is a large moulding, usually placed at the base of columns. The torus has its diameter, vertical, and parallel, to the axis of the column. The plinth, is the short cylinder which supports the torus.

5. Make a quarter-round with its fillets. (fig. 5.)

6. Make a quarter-round reversed, with its fillets. (fig. 6.)

(7)

(8)

7. Make an ogee or talon with its fillets. (fig. 7.)

8. Make an ogee or talon with its fillets reversed. (fig. 8.)

The profile of the talon is formed by two arcs of a circle united at their end, and whose centres are on different sides of a right line which joins their extremities. This line, which is dotted in the figure, is cut in the middle by the arcs, and each half being taken for the base of an equilateral triangle, the summit or apex of the triangle is the centre of the arc. The right line which joins these two summits or centres of the arcs, passes through the point where the two arcs touch at the middle of the first right line.

9. The monitor must now require the pupil to draw the eight preceding figures, turned towards the left.

(9)

10. Make a pedestal. (fig. 9.)

Here the arcs, end to end, belong one to an ellipse, *and the other to a circle. The centres and axes are marked.

11. Make a vase or flower pot. (fig. 10.)

It will be recollected that this and the preceding figures of this Class, are flat representations of round objects.

(10)

12. Make a ewer and basin. (fig. 11.)

Here is a half ellipse joined to two quarter-circles. In the foot of the ewer, its handle and neck, the curves are fanciful. In this, and in all the following figures, the drawings represent round bodies.