The 1921 third edition of A Course of Pure Mathematics by Godfrey Harold Hardy is the second-most-popular ebook I post-processed for PG. In the aughts and teens, Content Provider and Project Manager Brenda Lewis was a prolific contributor to Distributed Proofreaders (DP), particularly for mathematical books. She and I collaborated on a number of DP projects.
A Course of Pure Mathematics was digitized during an active and exciting period for math at DP. Like other DP-produced LaTeX books of that era, we matched the spirit of the original typography while extensively hyperlinking the PDF file. More than usual, the book’s notation was modernized; Hardy’s use of \(\varepsilon\) and \(\delta\) is opposite the convention of the past half-century, for example. (If you have studied real analysis, you understand the distinctive pedagogical weight of this simple notational swap!) To uphold DP’s tradition of preserving the original, all changes were coded to be controllable by a few boolean flags in the LaTeX preamble.