Thursday, June 30, 2011

Jordanus de Nemore's Arithmetica

This is page 7 from an early printed edition of the Arithmetica of Jordanus de Nemore (early 13th century). The page contains theorems 14 through 19 of Book I. Rough translations are available here.

Wednesday, June 8, 2011

Galileo's Geometrical Compass

This image is from the 1640 printing of Galileo's Operation of the Geometrical and Military Compass. In this image, Galileo demonstrates how to find the height of a distant object by using the compass twice to sight the object at different distances.

Wednesday, June 1, 2011

Pacioli's Summa

This is the title page of the Summa de arithmetica, geometrica, proportioni et proportionalita, published by Luca Pacioli (1445-1509) in 1494. This was the most comprehensive mathematical text of the time and one of the earliest printed mathematical works. It contained not only practical arithmetic, but also algebra, practical geometry and the first published treatment of double-entry bookkeeping.

On this page (f. 36v), Pacioli illustrates one of the methods of finger counting prevalent at his time in Italy.