6 diagrams, 8 black and white photographs, and 2 photometry photographs relating to gravitation experiments performed by Charles F., Sr. Charles F. Bru Show more6 diagrams, 8 black and white photographs, and 2 photometry photographs relating to gravitation experiments performed by Charles F., Sr. Charles F. Brush, Sr., Papers Series 13: Photographs (1880s-1954) Box 39 Folder 5 Show less