Fowler's "Jubilee Magnum," slide rule
Fowler and Company, Manchester
1/2 x 4 3/4 x 5 in.
One sided circular slide rule looking like a very large poicket watch. two knobs - one at the 12:00 and the other at 1:30 position.
Hand calculation; Analog; Oughtred, William
Gift of Gwen and C. Gordon Bell