I am writing the first book from the American point of view about 19th century rotunda panoramas. These were the biggest paintings in the world,50 x 400=20,000 square feet, housed in their own rotundas which were 16-sided polygons. Chicago in 1893 had 6 panorama companies and 6 panorama rotundas. F.H.Day was secretary of The Cyclorama Compana, Philadelphia,Pa. I have info to share.