Arithmetica Infinita or The Accurate Accomptant's Best Companion Contriv'd and Calculated.

[Edinburgh] Printed for the Author, Deus nobis Haec Otia Fecit, Anno 1717/18. FIRST EDITION. Small oblong 8vo, 111 x 92, pp. [iv], engraved title page and letterpress recommendation by John Keill], 14 [engraved preliminaries], 126 [engraved table], 10 [ engraved tables of interest with separate title page], engraved portrait of the author before the title, bound in contemporary paneled calf, sometime neatly rebacked and recornered, spine with raised bands and olive label, slight browning, old stamps of the Patent Office Library, but well preserved and restored for this type of production, George Brown (1650-1730) was a Scottish arithmetician and minister, known for the invention of an arithmetical instrument, called Rotula Arithmetica—a device for simple addition, subtraction, multiplication, and division. Brown attended Aberdeen's Kings College, matriculating in 1664 and graduating in 1668. Then he worked as a teacher of mathematics in Edinburgh. Later on, he worked as a minister in Stranraer, schoolmaster in Fordyce, and from 1680 schoolmaster at Kilmaures. In 1690s, Brown invented Rotula Arithmetica and in 1698 he was given the sole privilege (something like patent) to frame, make and sell his instrument for the space of 14 years. Brown described his instrument in the book An Account of the Rotula Arithmetica, published in 1700 in Edinburgh. In the same year 1700 he published also another book, called A Specie Book, to be used in conjunction with the Rotula Arithmetica. The book contains currency tables, because many of the coins were not Scots-minted silver, but foreign currency, legal tender in Scotland, at values fixed by the Privy Council and Parliament.