Halden "Calculex" patent circular slide rule (5 inches diameter) in case
- Made:
- 1904-1907 in Manchester
- maker:
- J Halden and Company Limited
Halden "Calculex" patent circular slide rule (5 inches diameter) in case, c. 1906
Details
- Category:
- Mathematics
- Object Number:
- 1970-639
- type:
- circular slide rule
- credit:
- Mr. R.W. Cooke.
