The author would like to thank the Euler Society and its members for their encouragement in this work, and for many helpful conversations over the years at conferences and meetings. The author would also like to acknowledge that earlier versions of this work appeared as parts 2 and 3 of a three-part sequence of columns in *Opusculum* (Volume 3, issues 1 and 2), the newsletter of that society. The original versions of these newsletters can be accessed at http://faculty.washington.edu/etou/eulersoc/press.htm.

Dominic Klyve is Professor of Mathematics at Central Washington University. He is the author of more than 50 papers in number theory, the history of mathematics and science, and applied statistics. His interdisciplinary works have appeared in journals ranging from Gastrointestinal Endoscopy to Shakespeare Quarterly. Klyve has been nationally recognized for promoting the use of primary sources in the teaching of mathematics, and currently serves as a PI on the National Science Foundation TRansforming Instruction in Undergraduate Mathematics via Primary Historical Sources (TRIUMPHS) grant to develop and study classroom materials for this purpose. He was a 2014 winner of the MAA’s Henry L. Alder Award for Distinguished Teaching by a Beginning College or University Mathematics Faculty Member, and currently serves as editor of the *College Mathematics Journal*.