Group of sixteen (16) ink drawings on vellum by student Ada Allanach, Vesper George School of Art (operating 1924-1983), Boston.
The drawings seem to be part of two (possibly three) separate sequences illustrating light and shadow projections from and on forms of gradually increasing complexity — from flat planes through compound geometric solids, with conditions and light sources changing across the set.
Personally, I love their dynamic, complex geometry, and that these renderings feel as much like plans for the construction and alignment of a shadow as they do observations of the phenomenon.
Dated 1929.