on PERSPECTIVE.
P S, and making the Point p be the ſame as P. then join each Diviſion of this Line, to the

correſpondent Diviſion of the Line h i; and the

Dial ſought, will be drawn: p being the Foot

of the Style, and p s the Horizontal Line.

Fig. 67.

The Baſe Line is h i; p s is the Horizontal

Line; p the Point of Sight; and E O, or C P,

of Figure 66. is the Length of the principal

Ray.

Fig. 66,

67.

67.

Now, ſuppoſe the Plane p s h i, to be ſet per-

pendicularly upon the Horizontal Dial, in ſuch

manner, that the Line h i coincides with H I,

and the Point o with O. Suppoſe, moreover,

that thro’ the Extremity of the Style, which we

conſider as the Eye, Lines are drawn in the Ho-

rizontal Plane, parallel to the Hour-Lines of

the Dial; it is evident, that theſe Lines will

meet the Horizontal Line p s, in the Point al-

ready prick’d down; and conſequently , the
Appearances of the Hour-Lines, are the Lines

joining the Diviſions of the Lines h i and p s.

13.

If the Line H I happens to meet the Meri-

dian; the common Method, by the Horizontal

Dial, is eaſier than this.

123. To draw inclining Dials.

Theſe Dials are drawn in the ſame manner as

Vertical ones; the following Preparations being

firſt made.