<span>Typed letter from A. C. Dustin to Charles F., Sr., thanking Brush for sending a copy of his paper, Persistent Generation of Heat </span><span>in Some Rocks, to DustinCharles F. Brush, Sr., PapersSeries 1: CorrespondenceSubseries 2: Acknowledgments (1921-1929)Box 3Folder 5</span>