Seth Partridge (1608-1686)
London: Robert White, 1648
Rare Book Collections, GTC G440
Open to: “The description of all the four faces of every one of the ten Rods….” opposite page 6.
Partridge describes this calculating device, invented by John Napier (1550-1617), as “the Art of Numbring by Rods, whereby the tedious operations of Multiplication, and Division, and of Extraction of Roots, both Square and Cubick, are avoided, being for the most part performed by addition and subtraction.”
Napier’s own book on “Napier’s rods” (or “bones”) and other calculating techniques, Rabdologiae, was published in Latin in 1617. Partridge explains that “according to my dark and mistie understanding in the Latin tongue, I collected out of the Lord Napiers Latin book, some rules and notes of the use of the Rods into English, for my own private use.” He was eventually persuaded to publish his notes, “for the use of all.”