The elements of Euclid, [electronic resource] : viz. the first six books, with the eleventh and twelfth. In which the corrections of Dr Simson are generally adopted, but the errors overlooked by him are corrected, and the obscurities of his and other editions explained. Also, some of euclid's demonstrations are restored, others made shorter and more general, and several useful propositions are added. Together with elements of plane and spherical trigonometry, and a treatise on practical geometry. By Alexander Ingram, Philomath.