Typed postcard from Harrison W. Craver to Charles F. Brush, Sr., in acknowledgment of the Engineering Societies Library's receipt of Brush's third pap Show moreTyped postcard from Harrison W. Craver to Charles F. Brush, Sr., in acknowledgment of the Engineering Societies Library's receipt of Brush's third paper on gravitation. Charles F. Brush, Sr., Papers Series 1: Correspondence Subseries 2: Acknowledgments (1921-1929) Box 3 Folder 1 Show less