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 uses 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. 

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Index of Mathematical Treasures