Grounding

[sonicus]

Here is an explanation of  versions for the UK ;
http://wiki.answers.com/Q/What_is_the_household_AC_electrical_power_service_in_the_UK

[sonicus]

There is important  info here regarding  230 VOLT AC 50HZ SINGLE PHASE VOLTAGE  in Europe:
http://wiki.answers.com/Q/Can_you_explain_about_the_use_of_the_neutral_wire_in_240_volt_hookups

[cozmik_cowboy]

Be afraid, Hugh - be very afraid!  I love old houses - am almost done restoring my second 100+yo one - but period authenticity is not always a good thing.  You need a complete rewire to current code before you plug anything in!  I'm betting there's knob-&-tube wiring behind that outlet, and modern devices can easily draw enough juice to overheat that stuff to the point of fire.  If you rent, make the landlord fix it, or sic the building inspectors on him.
 
Peter

[hb3]

Oh, well, it's not so bad. It's more updated than that -- all the plugs are converted except that one and one next to it, as they were covered up for years and years. I'm definitely gonna buy one of those testing things, though -- didn't know those existed. That should be useful.

[cozmik_cowboy]

Ah - you were going for shock effect!  It worked.  Do check the wiring behind the outlets, though; I've seen many a brand-new 3-prong socket hooked to ancient wires.
 
(Edited to confess I honestly didn't catch the pun until after I'd posted)
 
Peter
 
(Message edited by cozmik_cowboy on July 26, 2011)

[hb3]

Well, that one does look shockingly old. Hee hee.  
 
I'm more and more concerned about noise, though. I'm trying to record with my pedals, and there's a hell of a lot of buzz that doesn't seem so loud when you're first listening to it, but that shows up very badly on a recording.