GENAILLE’S RODS — A PERFECTED FORM OF CALCULATING RODS FOR MULTIPLICATION AND DIVISION
Stock Number: 10322
For sale, antique 19th century rods to calculate, in an easy way, multiplication and division. Consisting of ten wood rods, covered in printed paper, and used with a fixed rod. Instantaneous results.
6-3/4 inch (17 cm) long rods
Country of manufacture
GENAILLE’S RODS — A PERFECTED FORM OF CALCULATING RODS FOR MULTIPLICATION AND DIVISION, French, 1885, signed on the card box “Les Réglettes Multiplicatrices, Appareils à Calculs Exacts et Instantanés pour Simplifier la Multiplication et la Division. Inventés par Henri Genaille et Perfectionnés par Edouard Lucas,” published in Paris by E. Belin. The ten wood rods, each 6-3/4″ (17 cm) long, are covered on all four sides with printed paper columns, and are used in conjunction with the fixed rod. The results are instantaneous, for numbers as large as ten digits. The set is complete and in excellent condition, the original box with instructions, fine.
These rather complex rods each present, using the four sides, tables and diagrams for four different digits (identified on the top and bottom of each rod). There are nine rows, aligning with the numerals 2 through 9 on the left-most (fixed) rod. Black triangles align with graded columns of digits to give multiplication tables, etc. In use, for multiplication one simply selects the rods to form any multiplicand, starts with the right-most digit, and follows the path of the triangles to read out the result.
The inventors developed various aides for calculation, all apparently published in 1885. We have had their “Réglettes Néperiennes” (Tesseract Catalogue 72, Item 41), their “Financières” rods for commercial calculations (36 /47), their “Multisectrices” for division (47/51), and now for the first time their stunning set of “Multiplicatrices.” An extremely rare, ingenious variant.
Ask the Dealer
David and Yola Coffeen both have enjoyed academic careers, as planetary astronomer and as linguist/educator. But since 1982 (yes, 1982!) they have been full-time dealers in early scientific and medical instruments, under the name Tesseract. Selling primarily by catalogue (over 100 issued so far) they also have a web presence at www.etesseract.com, and can be contacted at firstname.lastname@example.org.