I've been searching for the Latest (56th) edition of "How To Run a Lathe". I couldn't find it, but I did find the 55th edition. I uploaded it to VintageMachinery.org so anyone can download it. It's in two parts.
South Bend Lathe Works - Publication Reprints - How To Run A Lathe 55th Edition | VintageMachinery.org
South Bend Lathe Works - Publication Reprints - How To Run A Lathe | VintageMachinery.org
South Bend Lathe Works - Publication Reprints - How To Run A Lathe 55th Edition | VintageMachinery.org
South Bend Lathe Works - Publication Reprints - How To Run A Lathe | VintageMachinery.org