If I can't get a answer here I don't know where else to look.
The Problem
One of the slides among my collection of DR computers is different from the rest. It looks like this:
Drift lines are there, speeds are there, but the cross lines are not arcs in the normal manner, and there are those 'odd' Away-To arrows along each side. It is a two sided slide with speeds 180 - 370 on one side and 380 - 570 on the other. The maximum drift shown on the slide is 2° either side. The computer element associated with it is the Computer DR Mk 4A (high Speed version).
The Question?
What was the slide used for and, if possible, how was it used. A bonus would be to know for which systems/ops it would be used. Any indication or suggestion as to where I might continue the research would be welcome. (I tried 3456 but nothing came up in the editions available to me).
Keg