Genaille`sche Stäbe

Rechenstäbe für die Division

1885

Genaille` bars

Calculating bars for division

1885

The engineer Henri Genaille became aware of the problem of the decimal transfer of the Napier bars in 1885 through the mathematician Edouard Lucas. He subsequently developed new staffs for multiplication and division. The shown bars can be used for dividing. To do this, you place the bars next to each other in such a way that the uppermost numbers give the dividends. To the right of it the index stick is created. You start by searching for the divisor in the right column of the index bar. In the following, one remains in the horizontal segment in which the divisor is located. You go to the top number of the left stick in this segment, follow the line from left to right across the sticks and you get to a number on the index stick. The numbers on the lines form the result. E.g. 98281 divided by 4: You start with 2 and follow the lines: 4, 5, 7, 0, 1 and get the result 24570, rest 1.
Inventory number:
FDM9051

Inventor:
Genaille, Henri

Year of invention:
1885

Year of manufacture:
1885

Main category:
Einfaches Rechenhilfsmittel

Dimensions (H x B x T):
2 x 12 x 18 cm

Weight:
168 grams


Literature:
  • Conservatoire Nationale des Arts et Métiers: Instruments et machines à calculer. Ausstellungskatalog Conservatoire National des Arts et Métiers. Paris 1942, p. 87ff.
  • Marguin, Jean: Histoire des instruments et machines à calculer. Trois siècles de mécanique pensante 1642-1942. Paris 1994, p. 35ff.
  • Weiss, Stephan: Die Rechenstäbe von Neper, ihre Varianten und Nachfolger. Ein Beitrag zur Geschichte des instrumentalen Rechnens. Ergolding 1985, p. 162ff.
  • Williams, Michael R.: „From Napier to Lucas", in: Annals of the History of Computing 5, 1983, p. 279ff
  • Williams, Michael R.: A History of Computing Technology. Los Alamitos, Calif. 1997 (2. Auflage), p. 93ff.
This object is currently on display on the 2nd floor.