http://www.inventioninfo.info/logfiles/1319/invention-timeline-louis-bertrand-castel-a-jesuit-mathematician-and-philosopher-inventor-of-the-instrument-of-an-instrument-called-the-ocular-harpsichord Invention timeline, news, and information. Wed, 07 Jan 2009 01:46:09 +0000 http://wordpress.org/?v=2.0