I purchased these drawings from a dealer in Romania and was not quite certain what to expect, but they are absolutely gorgeous--very finely done, and quite striking, especially all together, so I'm listing them as a set and think I would would frame them up together more or less just a shown.
Clockwise from upper left, they depict details from 1)a column in the Hagia Sofia mosque, Constantinople (Istanbul); 2) an unnamed Byzantine sculpture; 3) a column at the Basilica of San Vitale in Ravenna, and 4)an unidentified sarcophagus, also in Ravenna, and I would guess at San Vitale as well. The drawings are done in black ink with what appears to be a sepia wash over them, which really makes them pop, then were very carefully cut out and mounted to backing sheets.
Each measures 3 1/2" x 5 1/2". Very good condition overall - the backing papers show stains here and there but really not detracting at all. On the back one can see the outlines of where glue was applied to mount the drawings to the backings.