[I]t may not be amiss to set down here two Approximations I have…

I make no difference between the Plane of the , and any other Plane whatsoever; for since Planes, as Planes, are alike in Geometry, it is most proper to consider them as so, and to explain their Properties in general, leaving the Artist …

The true and best way of learning any Art, is not to see a great many Examples done by another Person, but to possess ones self first of the Principles of it, and then to make them familiar, by exercising ones self in the Practice. For it …

I found it absolutely necessary to consider this Subject entirely anew, as if it had never been treated of before

And I was forced to invent new Terms of Art

Considering how few, and how simple the Principles are, upon which the whole Art of PERSPECTIVE depends, and withal how useful, nay how absolutely necessary this Art is to all forts of Designing; I have often wonder'd, that it has still …

I have endeavour'd to make every thing so plain, that a very little Skill in Geometry may be sufficient to enable one to read this Book by himself.