For sale initial (not reprint) 4 Volume Set of Knight's American Mechanical Dictionary from 1872. Released by Houghton Mifflin and Company of Boston. Volumes 1-3 includes 2831 pages of basic mechanical encyclopedic information of that era. Volume 4 consists of 960 pages of descriptions of Tools, Instruments, Machines, Processes, and Engineering with Indexical References to Technical Journals from 1. Each volume contains an unbelievable array of text and in-depth illustrations on thousands of topics. These books are in great condition ... pages are still excellent after 142 years.