Typed letter from Samuel L. Smith to Charles F., Sr., thanking Brush for sending Smith a copy of the fourth paper on the theory of kinetic gravitation Show moreTyped letter from Samuel L. Smith to Charles F., Sr., thanking Brush for sending Smith a copy of the fourth paper on the theory of kinetic gravitation by Brush Charles F. Brush, Sr., Papers Series 1: Correspondence Subseries 2: Acknowledgments (1921-1929) Box 3 Folder 7 Show less
Typed letter from Samuel Lewis Smith to Charles F., Sr., thanking Brush for sending a copy of his paper, Persistent Generation of Heat in Some Rocks, Show moreTyped letter from Samuel Lewis Smith to Charles F., Sr., thanking Brush for sending a copy of his paper, Persistent Generation of Heat in Some Rocks, to Smith, who plans to pass it on to the head of the Metallurgical Department Charles F. Brush, Sr., Papers Series 1: Correspondence Subseries 2: Acknowledgments (1921-1929) Box 3 Folder 5 Show less