Make Unnamed
Model No name
1. This rule was a simple advertising rule for a British company - Boulton and Paul.
2. The rule is basically made of cardboard covered in plastic. The cursor is also made of plastic.
3. The rule has the words PATENT Dr. Ing. Seehase. The patent application was made in Germany on 28 March 1939 in the name of Dr Ing. Hans Seehase; the patent was granted on 8 March 1940; the patent was published in 4 September 1944. The patent was number DE727007. Given what was happening in Germany at that time it is interesting that the process of publishing the patent still continued. (Antwerp was freed by a British tank division on the day the patent was published.) Dr Seehase had another patent for slide rules granted in 1956.

Front view

Back view

Detail -cursor

Detail - patent

Detail - patent application

Manufacturing date The patent was published in 1944 but it was probably made in the 1950s
Length 5 1/2"
Material Cardboard and clear plastic.
Scales A [B, C] D  (but not named as such)
Cursor Plastic