Lot 111: DODGSON, Charles Lutwidge (1832-1898, "Lewis Carroll"). The Formulae of Plane Trigonometry, printed with symbols (instead of words) to express the "Goniometrical Ratios" . Oxford: James Wright for the University Press, 1861.

DODGSON, Charles Lutwidge (1832-1898, "Lewis Carroll"). The Formulae of Plane Trigonometry, printed with symbols (instead of words) to express the "Goniometrical Ratios". Oxford: James Wright for the University Press, 1861.

4υo (218 x 180mm). UNOPENED self wrappers, as issued, printed correction tipped-in on p.19.

FIRST EDITION OF THIS RARE PAMPHLET, in which Dodgson invents and explains symbols for the terms of Plane Trigonometry. Dodgson refers to this work in a letter to his sister, Mary Collingwood, on 20 February 1861, where he describes it as "Collection of Formulae (1/2 done)," (Letters p.48). Another work in progress he mentions in this letter, 'Collection of Symbols' probably refers to this work as well: "Dodgson may have developed the two parts separately, combining them later when he saw that it made sense to do so" (Mathematical Pamphlets, p.121). VERY RARE: only the Nicholas Falletta copy has sold at auction in the last 30 years (sold Christie's South Kensington, 30 November 2005). Williams-Madan-Green-Crutch 27; Mathematical Pamphlets 5.