I found two slide rules(Load Adjuster) today thought I would show. The first post is for a Lockhead hudson that is in orig box the other is not.
They are for use of various indicators of load (weight) for different compartments and the materials to be loaded therein. Each item to be stored on the aircraft, including fuel, bombs and crew, has a weight which adds to a shift in the balance of the aircraft (the centre of gravity) away from its centre line thus tending to cause it to turn towards the point of this mass. This is the turning "moment" of the load. The accumulation of various loads in different parts of the aircraft needs to be balanced out so that the aircraft's tendency to stray from its course is minimised. The scales are not logarithmic but simple linear scales because the rule's function is to add the moments as they are distributed over the aircraft.