Arithmetical illustrator: containing explanations of the rules and most intricate parts of arithmetic, together with solutions of the most abstruse questions throughout the American tutor’s assistant : in a dialogue between a tutor and his pupil / by William Douglass, 660 - Chandler Collection no. 3, Volume: Archives Chandler Collection no. 3. Clarion University Archives.

Arithmetical illustrator: containing explanations of the rules and most intricate parts of arithmetic, together with solutions of the most abstruse questions throughout the American tutor’s assistant : in a dialogue between a tutor and his pupil / by William Douglass, 660 - Chandler Collection no. 3, Volume: Archives Chandler Collection no. 3. Clarion University Archives. http://as-clarion.klnpa.org/repositories/2/resources/914 Accessed January 13, 2026.