The 'Tachylemme' ready reckoner, c 1876.

Image number: 10327827

The 'Tachylemme' ready reckoner, c 1876.

Invented by C L Chambon, the 'Tachylemme' was used to calculate the daily interest on sums of money at various rates.

Image number:
10327827
Credit:
Science Museum/Science & Society Picture Library
Date taken:
20 October 2003 18:54
Image rights:
Science Museum