Dalles carrés - tesselation perspective (double-sided)

Single leaf with drawings on both sides, 8.25 x 6.25 inches. Loosely mounted in double-window acid-free mat and archival sleeve, 14 x 11 inches, viewable from either side. Very Good condition with light edgewear. From a mid-19th century French student manuscript on architectural and mechanical drafting containing notes for computational and perspective drawing, studies on light and shade, reflection, etc.