I am grateful that this book is now preserved electronically so that new generations can profit from it (see TB and SDAI comments below). But something has occurred to me, copies of this volume still in private hands or in large libraries are still intact and available for use, and will be so for a long time (acid-free paper!).

Can we expect that facsimiles on electronic media will still be around 58 years from now? Not just this book, but any other book from past, present or future. Scholars still have access to centuries-old books, which with reasonable care have very long shelf-lives. Electronic copies are at the mercy of very quickly changing technologies. Even if copies of this book exist on CD a century from now, do we have any guarantee playback equipment will be available to reproduce them; not to mention the interest and desires of future generations may not feel it necessary to transcribe them into whatever form is current then.

Perhaps I can provoke a comment from our favorite librarian?