3 Typed letters between Charles F., Sr. and Alfred Cowles regarding the life and work of German physicist Alfred H. Bucherer in relation to Brush's wo Show more3 Typed letters between Charles F., Sr. and Alfred Cowles regarding the life and work of German physicist Alfred H. Bucherer in relation to Brush's work in gravitation and Einstein's theory of relativity. Includes reprint of Bucherer's work entitled The Movement of Planets According to the Quantum Theory, and Critical Comment on Einstein's Gravitational Equations. English translation printed by McIlroy and Emmet, New York, 1923. Charles F. Brush, Sr., Papers Series 1: Correspondence Subseries 3: Business and Professional (1876-1931) Box 4 Folder 6 Show less