Handwritten postcard from Charles Sawyer to Charles F., Sr., thanking Brush for sending latest gravitation paper and informing Brush of groundbreaking Show moreHandwritten postcard from Charles Sawyer to Charles F., Sr., thanking Brush for sending latest gravitation paper and informing Brush of groundbreaking for addition to college library. Front of postcard has picture of Hiram, Ohio’s library and observatory Charles F. Brush, Sr., Papers Series 1: Correspondence Subseries 2: Acknowledgments (1921-1929) Box 2 Folder 14 Show less