_A double Square in Perspective._
The double Square A is made after the same manner as the former, by
transporting, either with the Compasses, or folded Paper, the Breadth of
every Line, as you see the Points 1, 2, 3, 4, 5, 6, on the Ground-line
mark’d with the same Numbers; and from these draw Visuals to the Point
of Sight. Then transfer the Points of Length 7, 8, 9, 10, into the
Ground-line, as you see also in the same Numbers; and direct their Lines
to the Point of Distance E. Where these intersect the Visual 6, 7, O,
make Parallels to the Ground-line, and the Square is complete. The same
is done in describing the middle Square, and that on the other Side.