Slide rules HOME page COLLECTION SPECIALISED RULES
Make P Hopp (personal communication) suggests it was made by Unique and it certainly has the look and feel of a Unique rule.
Notes This is a specialised rule for calculating concrete volumes. It is marked "C & G Concrete Limited" on the back.

Front view
9901-concrete01.jpg (13774 bytes)

Detail - instructions
9901-concrete02.jpg (9190 bytes)

Detail - front
9901-concrete03.jpg (14431 bytes)
Model  
Manufacturing date  
Length 5"
Material Plastic on wood
Scales Labelled A, B, C and D but not related to normal scales of same name.
Cursor None
Hair lines  
Documentation None but full instruction on slide.
Condition Good