Mathematical Treasure: John Caswell’s Trigonometry

Englishman John Caswell wrote a book with the title A Brief (but full) Account of the Doctrine of Trigonometry, Both Plain and Spherical, which was published in 1685. Caswell was a student of John Wallis and held the Savilian Chair of Astronomy at Oxford from 1709 to 1712.

The page below shows the first page, which contains a list of symbols that Caswell used in this trigonometry textbook. Some, but not all, of the symbols are still in use today.

A complete digital scan of Caswell’s Trigonometry  is available in the Linda Hall Library Digital Collections. The call number is QA33 .W343 1685. 

Images in this article are courtesy of the Linda Hall Library of Science, Engineering & Technology and used with permission. The Linda Hall Library makes available all existing digital images from its collection that are in the public domain to be used for any purpose under the terms of a Creative Commons License CC by 4.0. The Library’s preferred credit line for all use is: “Courtesy of The Linda Hall Library of Science, Engineering & Technology.”

Index of Mathematical Treasures