Non-Euclidean geometry caused a re-examination of the teaching of geometry based on Euclid's Elements. This curriculum issue was hotly debated at the time and was even the subject of a book, "Euclid and his Modern Rivals", written by Charles Lutwidge Dodgson (1832–1898) better known as Lewis Carroll, the author of "Alice in Wonderland". In analytic geometry a plane is described with Cartesian coordinates : "C" = { ("x,y") : "x", "y" ∈ ℝ }. The points are sometimes identified with complex numbers where ε ∈ { –1, 0, 1}. The Euclidean plane corresponds to the case since the modulus of is given
Edwin Dodgson priest in 1874, and served his first curacy at Odd Rode in the Diocese of Chester. Following this he served as curate at Helmsley (1875-1877), and at All Saints, Shrewsbury (1877-1879). His subsequent ministry was one of self-sacrifice and dedication, marred by ill health and depression. Dodgson was appointed as Principal of the (UMCA) Kiungani School in Zanzibar in 1879, where he served under Bishop Edward Steere. However, as his brother Charles noted, "the ague was too much for him there". In 1880 he was appointed by the Society for the Propagation of the Gospel (SPG) as missionary and school