Isaac Todhunter's Plane Trigonometry for the Use of Colleges and Schools, With Numerous Examples was first published in London by Macmillan and Co. in 1874. The preface tells us that the book "contains all the propositions which are normally included in treatises on Plane Trigonometry, together with about a thousand examples for exercise. The design has been to render the subject easily intelligible..." One shudders to think what would happen if one attempted to use it today in either colleges or schools. In fact, I wonder if students ever found it "easily intelligible"!
Today, Todhunter's book is of interest mainly for historical reasons. It is interesting to see how much he includes (all the way to series expansions, complex exponentials, and methods for summing trigonometric series) and how densely packed with formulas his text is, making very few concessions to the student. Teachers looking for hard exercises are likely to find many of them in here.
This edition of Todhunter was published by Elibron Classics, a new company that is scanning old books (especially, it seems, from the library of the University of Moscow) and making them available in both electronic and paper editions. The books are print-on-demand editions and are photographically reproduced, so the quality of printing and binding is not always the best. Still, in many cases they provide the only easy way to own a copy of older books.
Fernando Q. Gouvêa (email@example.com) is the editor of FOCUS and MAA Online.