I was a very callow youth of 8 in 1940 but I well remember the paranoia at the time regarding all foreigners. There was rumoured to be a “fifth column” set up before the war to assist the Germans, etc., etc., etc. Any parachutists were to be regarded with great suspicion, my father coming back from the pub one night saw a parachute descending from an aircraft. He immediately suspected the worst and watched it closely and was surprised to be blown over by the blast of a landmine coming down about half a mile away. We went next morning to see the crater and the damage to surrounding houses in the small hamlet where it fell. I was most surprised at the depth of the crater and picked up a small piece of silk rope from it.
But we boys were told that the Germans were coming and that when they did we had to put sugar in the petrol tanks of their vehicles

There were two varieties. The type in my pics above was the navigators type, you can see the remains of two of the four feet on the top pic, where it lay on the chart table. This was because most use was done on the circular window where wind speeds and direction were fiddled. One then turned the contraption over to use the circular slide rule on the bottom to calculate times and distances etc., as well as determining true airspeeds and heights with the little scales in the windows.
The other type had that section on the hinged lid and with leg straps, for use by a pilot who had it strapped to his knee. These were in the main used by the PR pilots, I cannot begin to comprehend how these men managed 4 hour plus sorties over a very hostile continent, and maintained accurate navigation in the very confined space of a Spitfire cockpit.
There was a later variation that came with the jet age. In this the cloth band was replaced with a plastic slider which could be reversed to give a greater range of speeds. This slid through another plastic gimmick with a 360 rotating window to do the same job.

Did it hit it?:p

One of those shots that makes you wonder when it happened last.

Adrian

Some time in the early 1959s when the T20 was used as a navigation trainer in Rhodesia

These petty restrictions are typical of what passes for common sense at all levels of government here now. No wonder the country is going down the plughole.

Roll on the Revolution!

I would love to have an indicator unit from AI Mk 10 (SCR720)

Thanks for that. One will be a keeper for me

And thanks from me too. As he says “You have to be in the right place at the right time”, but he made full use of that time.