The Invention of the Track Circuit, by American Railway Association 45179 [Subtitle: The history of Dr. William Robinson's invention of the track circuit, the fundamental unit which made possible our present automatic block signaling and interlocking systems] [Link: http://www.gutenberg.org/4/5/1/7/45179 ] [Files: 45179.txt; 45179-h.htm] Thanks to The Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive/American Libraries.) Regards, Al