Preliminary Discourse--Natural Philosophy, by John F. W. Herschel 54897 [Full title: Preliminary Discourse on the Study of Natural Philosophy] [Link: http://www.gutenberg.org/5/4/8/9/54897 ] [Files: ; 54897-0.txt; 54897-h.htm] Thanks to Sonya Schermann, Charlie Howard, and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) Regards, Al