A description of the visible numerator, with instructions for its use ... Designed to impart to learners a clear and an adequate knowledge of the principles of arithmetic, and to accompany the apparatus
Early works
95, [1] pages 22 cm
6321745
v. 1. Description of the visible numberator with instructions for its use
v. 2. Series of illustrative plates, designed to aid learners in acquiring a philosophical knowledge of the principles of arithmetic and to accompany the visible numerator