Perspective Drawing . 
subject will convince any mind, capable of reflection, 
that, to accomplish the general ends that even most 
painters have in view with respect to that art, it is only 
necessary to know the use of the points of sight and hori- 
zontal line . For while men have agreed to avoid bevel 
lines in all their constructions that are intended for use 
or habitation, we shall only want as much knowledge of 
the art as will enable us to put these into perspective, 
and to assist us at first, before, by practice, we have at- 
tained a correct eye ; for practice, daily practice, will 
soon do all the rest, even by barely drawing the interior 
of a large apartment or gallery, with the objects continu- 
ally before us in common use. • 
To save time, however, and to imprint the few lessons 
necessary to be given on the mind of a learner, I have, 
some time back, made use of the following simple contri- 
vance, which I now send to you, as the most likely means 
of universally promoting this necessary preliminary stu- 
dy, where the first general principles have been instill 
cd: — Take a sheet of paper of an octavo size, and rule 
it with very black ink, from A to B (fig. i, plate 7). 
This represents the horizontal line; then fix a point in 
the centre, at C ; this we will call the moveable point of 
sight: afterwards cross it, as in the plate, with as many 
diagonal lines as you please ; and thus you have an in- 
strument prepared that will be a sure guide to an inexpe- 
rienced eye, in taking the perspective lines of all objects 
placed at rigb t angles ; such as streets, buildings, churches, 
apartments, &c. by merely placing it under the leaf you 
mean to draw them on from nature, so as to see them 
faintly through, as boys do their writing-copies, when 
young and inexperienced. 
But, to make this instrument more complete, we should 
add a plate of glass of the same size as the leaf of the 
drawing-book, on which the like dark lines should be 
