MORLAND, Samuel

The Description and Use of Two Arithmetick Instruments. Together With a Short Treatise, explaining and Demonstrating the Ordinary Operations of Arithmetick. As likewise, a Perpetual Almanack, and several Useful Tables

Colophon: 'Printed, and are to be Sold by Moses Pitt at the White-Hart in Little-Britain, 1673'

Small 8vo; various paginations, 25 plates

Collation: A8 B–F8 A8(–A8) G8(–G8) B8 ✳8

A landmark text by the courtier and inventor Samuel Morland (1625-1695). Preceded in the bibliography on modern computing only by works on the sector, Napier's Bones, and Pascal's manual for the 'Pascaline'. This, then, is the very first book in English on a mechanical calculating machine.

Here Morland introduces his machines for addition and subtraction (of currency), and for arithmetic. The book is also a compendium on calculation, including a perpetual almanac, tables of feasts and eclipses, and much else besides.

Two Arithmetick Instruments is a highly unusual production. The engravings are very fine, and some pages are printed in letterpress on one site and copperplate on the other. But it is a bibliographic conundrum, with many pagination errors and no standard collation. This copy is unusual in having all the plates fully intact, and lacks only the portrait frontispiece.

Fair condition: text and plates in very good condition, noting some faint staining to the lower half of the first 7 or so leaves; disbound, retaining early boards, spine separated and therefore due a sensitive rebind.