The PREFACE. Reaſons that induc’d me to publiſh the follow-
ing Work.

Having ſome Years ago buſied my ſelf in
drawing Figures by the common Methods, I
found out ſeveral Compendiums; which, by
diligent working, naturally enough fall in
one’s way, without being entirely beholden
to the Induſtry of others: And theſe firſt
Succeſſes made me hope for others more
conſiderable; and ſo I thought that a more
narrow Inſpection into the Theory of Per-
ſpective, might furniſh me with Rules more
general, for making the Practice thereof
eaſy.

I then thought upon ſeveral Methods to this
Purpoſe; but, being ſuſpicious that they were
not ſo eaſy {as} they appear’d, I have try’d
their Goodneſs, by exactly applying them to
different Subjects; and have nicely examin’d
all the Caſes, and order’d it ſo {as} not to be de-
ceiv’d by certain Operations, which at firſt
ſeem eaſy, but, when put in Practice, are
quite otherwiſe. Moreover, at convenient
Times, I look’d over the beſt Part of the
Authors of this kind, (whoſe Number is
increas’d very much, without any manner of
Neceſſity) ſome of which being advantagi-
ouſly diſtinguiſh’d among the Crowd, have
been very uſeful to me: But I dare affirm,
there are but a very few that give a new
Turn to the practical Part of Perſpective.