Aussie,
No I think it might have been 32VAC I got confused with.
The 3rd pic of the post by Bill, was in fact used by light Industrial Spot Welders here.
The pin configuration was meant to ensure that no other equipment could be plugged into that socket.
It is indeed correct there was no official standard as to the live/neutral connections certainly up to the 1950's. This is why on old bakelite plugs you'll see only the "E" designation and not "L" (or "A") and "N".
At that stage, the only people allowed to install this sort of gear would have been Registered Electricians and thier Apprentices, under instruction, mind you, any worker like this would have been able to work that out for themselves, with a simple Bell test.
It is also interesting to note that up until the late 50's it wasn't required to earth domestic GPO's if there was no other earthed fittings in the same room. For example, in a bedroom it was not considered necessary to run an earth wire to the GPO, whereas in a kitchen it was required. I was quite suprised the first time I'd seen it for real but I can see that you could have gotten away with it.
I'm not actually aware of a rule like that over here, from the Regs that I have, you were required to Earth everything.
those cord-line switches in your picture are terrible. They fail the moment you insert a 100w light bulb in the table lamp instead of a 60w. I've never checked but I cant believe they are rated at 10A.
Kiwi, no they aren't as far as I'm aware.
I heard figures of 100 or 300W but there is no way that they would carry 2300W.
Proof of the pudding is when you try and switch an inductive load with them, say a twin lamp with Compact Fluorescent lamps in it.
I've never liked cord-line switches or dimmers, they are in my opinion just a stop-gap solution.
[quote]After all, the minimum size of cable allowed to feed a 10A outlet is 1.5mm which is rated at 16A. This is still a requirement isn't it ?{/quote]
Just because it's a minimum size, there is no stipulation to use it.
I'd never use 1.5mm to feed Socket-Outlets, no matter how small the house was.
Under my training you always used 2.5mm and protected it accordingly.
1.5mm was for lighting circuits.