:: A.A.S. R.A. Picture Gallery - View Picture The Ishango Bone Description: A bone from baboon discovered in 1960 by Jean de Heinzelin de Braucourt in Belgian Congo near Lake Edward. Dated back to between 9,000BC-20,000BC. May be it's a tally stick. At the top of the bone there is a piece of quartz. Possibly for writing. There are 3 rows of carved notches. The markings on two of these rows each add to 60. The first row is consistent with a number system based on 10, since the notches are grouped as 20+1, 20-1, 10+1, and 10-1, while the second row contains the prime numbers between 10 and 20! A third seems to show a method for multiplying by 2 that was used in later times by the Egyptians. Additional markings suggest that the bone was also used a lunar phase counter. Object size: 102 mm City: Brussels Country: Belgium Location: The Royal Belgian Institute of Natural Sciences Photographer: Ivaylo Grancharov Date: June, 2007 uploaded by Ivaylo Grancharov [back]