 The initial print run of 750 copies of Volume I and 500 copies of each of Volumes II and II from Cambridge University Press had been sold by 1922 when Rudolf Carnap wrote to Russell asking for a copy. Russell responded by sending Carnap a 35 page handwritten summary of the definitions and some important theorems in the work (Linsky 2011: 14–15). As no plates were available for a second printing, Russell began the work of preparing a second edition that appeared in 1925–27. The first was reset along with a new introduction and three appendices, and Volume II was reset as well. Volume III was reproduced by a photographic process, and so the page numbers from the first edition are the same in this volume. Principia Mathematica is still in print with Cambridge University Press.