Elements of Plane Trigonometry, by Hugh Blackburn 32973 [Subtitle: For the use of the junior class of mathematics in the University of Glasgow] [Link: http://www.gutenberg.org/3/2/9/7/32973 ] [Files: 32973-t.tex; 32973-pdf.pdf] Thanks to Andrew D. Hwang, Laura Wisewell and the Online Distributed Proofreading Team at http://www.pgdp.net (The original copy of this book was generously made available for scanning by the Department of Mathematics at the University of Glasgow.) David