four most aesthetic window proportions:

“On this Plate, the upper Window on the left Hand marked A is a true Square, the Height and Breadth being equal.

That of B hath for Height the diagonal Line of A, from Corners to Corner, they being all of one Breadth.

That of C hath for Height the Breadth and three Quarters, as shewn by Divisions on the Side and Bottom.

That of D is twice its Breadth in Height, than which Height none could exceed.”

William Salmon, Palladio Londinensis 1776