The PREFACE.
ing purſued at first, tho’ it requires a little more
Application, does afterwards ſave a great
many Hours Study, in an Art that always
appears difficult enough.
A Painter, in a ſhort Time, may learn this
Work, and make the Rules thereof familiar to
him: And if this Study be repeated from
time to time, for a few Days, he will find
the Benefit thereof, in diminiſhing his Labour
and Trouble.
But, that any one himſelf may ſee what
I promiſe in this Eſſay; take the following
ſhort Abſtract thereof. It is divided into
Nine Chapters: The Firſt, being as an In-
troduction to the reſt, ſhews the Uſefulneſs
of Perſpective, and gives you the Definiti-
ons of the Terms neceſſary for underſtanding
this Treatiſe.
The whole Theory is contain’d in the Se-
cond Chapter: Where, what has been found
moſt uſeful in that Matter, is therein re-
duced to Three general Theorems; viz. the
firſt, ſecond, and fourth: All the reſt is de-
duced from them, by way of Corollary. To
theſe Theorems, already known, are added
ſome new ones, ſerving for the Demonſtra-
tion of ſome neceſſary Propoſitions. Perhaps
it might be wiſh’d, that I had ſhewn the Way
that led me to the Truths which I diſcover: