How to date British plugs and fittings?

[Tim]

This isn't really bulb related but..I'm currently going through some old electrical plugs and receptacles in the collection and have noticed a common name appearing on a lot of old British stuff I have.? An example is pictured below.? I would like to prove to myself that the name "VITREOUS" is not a brand name or manufacturer's name.? I believe the name could refer to the porcelain finish or material this item is made from.? Does anyone know for sure the origin of this mark?

In the example below, I assume "GAC" are the initials of the actual manufacturer of this receptical.? Can anyone tell me who "GAC" is?

Lastly, I find many European electrical plugs and receptacles to be made of wood, which I think is interesting in itself!? I've been told this particular power receptical dates to around 1920.? At what point in time was it decided to drop the use of wood in electrical fittings in Europe?

[Chris W. Millinship]

I know very little about these early objects but find them particuarly interesting. Nowadays everything is strictly standardised and constructed with safety in mind but the sheer variety of styles and downright dangerous or bizarre construction of early fixtures and fittings is really quite fascinating. The fact that it seems no two pairs of plugs/socket-outlets are the same does make me wonder why more adapters are not to be found though!

That said, I do believe "Vitreous" refers to the porcelain construction and is indeed not a brand name. What exactly it means however, I do not know. Possibly refers to the fact that it is glazed or otherwise fired in a way that makes it impervious to moisture and suitable for being a directly insulating material. Just a guess really.

Surprised me too when I first saw wooden plugs and socket-outlets. Kind of goes against the standards of the current day that demand everything is flame/heat resistant. Wooden sockets and cotton/paper insulated cord aren`t exactly heat resistant, no wonder many people were afraid of electricity in the early days!

[Tim]

Yes, there’s something intriguing about mixing wood with electricity!  This stuff fascinates me.  I only wish more information existed today that documented these old pieces of history. Thanks for the info and comments. 

[Mónico González]

Hi Tim and Chris.
I have a huge couple of these porcelain bases, all of them manufactured here in Spain, some models were being made until no more than 10-15 years ago.
All of them has the classic European ring-shaped female contact structure instead the new "CE" standarized clamp-type contact.
Most of them doesn't match exactly with new safety plugs which has half plastic/half metal pins, but this is not a real problem.
Here, in Continental Europe there are two different gauges for round male contact pins of plugs:
- 4 mm dia. for standard non-grounded two-pole plugs, and
- 4,5 mm dia. for German "Schucko" side-grounded connectors.
Both systems has the axis of their pins equally spaced, at 19 mm.
so, in most cases, regular plugs can be connected to a Schucko receptacle without any problem, because these ones gives enough pressure to the male contact prongs from their internal clamps to avoid any risk of lack of continuity nor arcing. Opposite way not always are possible, because the thicker gauge of Schucko plugs.
At this days, after three months of intense brickworks and repairs, I'm too busy re-building almost all the electric installation at the ground floor at home, laying some extra circuits, including a new own indoor line, that will run around almost the wole house, for 125 volts. obtained from 220-230 mains by means of a big transformer. A tremendous job that I'm doing by myself, so I've removed all the older receptacles and switches, some of them to be regarded and substituted by new ones, and some others to be mounted again at their own place.
Many of these bases are well made and very sturdy genuine porcelain ones, so, I prefer to keep still them in use.
Two summers ago, I purchased a great batch of vintage electric stuff for household installations (sliding, basculant and rotary wall-mount switches, pear-shaped wire switches, plugs, brass-ceramic E27 and E14 sockets, porcelain fuses, and, of course, some ceramic bases). All these materials were found at a low price in an old hardware and household goods shop that was selling off all their stock at those days.
Really some of these appliances were noticeably better than their actual counterparts.
When I will have my website online again, I will post a collection of pictures about some of these rare and superb devices.
Best regards,
M. Gonz?lez.

[Tim]

Hi M?nico,

Thanks for the explanation regarding the difference between the grounded and non-grounded plugs and good luck with your home wiring project.? I’ll be looking forward to your new pictures on your website.? When will your website be back online?

[Mónico González]

Hi Tim!
At first, thanks for your interest on my home wiring work; it goes ahead, slowly but right, because there are near 1000 mts! of wire to fix and connect along almost the whole ground floor at home.
In second, about the rebirth of my website, it depends on disponibility of an adequate payment server, lacking of advertising and other nuisances.
As you knows, on last August I decided to "kill" my website due to some dissapointments with the old server's owners/administrators about theirs new advertising policy that implies the inclusion of a huge banner over the header of each page at the site.
I considered that those things goes against the solely divulgative and non-commercial purposes of my work, so, I did prefer to discontinue "Mis Bombillas" waiting for a better hosting provider, even if I would must pay per it.
Luckily a friend of mine? has a local cable TV station at Miguelturra, a town that are 4 Km apart from here. He also are in digital telephony and Internet ISP and LAN business too, so, he has his own servers for website hosting.
It's a curious experience to know exactly in wich machine and HDD your website files are stored, even being possible to "touch" it phisically, not as usually occurs, that one doesn't knows in which city and country around the world, or even within of wich satellite one's data are recorded and stored!
He have promised me that he will give me at least one-hundred MBs to host my website "Mis Bombillas", at a low price or perhaps for free, because I do often some contributions as sound technician, announcer and voice-character for commercials and spots for his TV station.
I hope that things will return to be completely normal, as far, in one or two months, including some pics of older Spanish electric appliances and fixtures.
Please, don't worry about continuity of my website, because I'm the main interested on to have it online again, so, when I will get my new URL, I will tell it you.
Regards,
M. Gonz?lez.

[debook]

Vitreuos basically means glass like, but porcelain is also often classed as vitreous.

Vitreous porcelain was probably first used around 1880 for electrical insulation. I would expect the best way to date it and British power sockets would be through patent records. It must have been used in the US too?

The reason that there is a huge variety of sockets, voltages and to a lesser extent caps was purely business. Initially it was because most of the companies were relatively independant and had to design their own standards but from about 1910 on and with the introduction of 'Free connection' it was to prevent people buying their electrical items from other electric companies - accordingly they would offer different prices for power and compete on that but once a customer was wired up they had no way of buying components from another company. On the other side of the fence, wealthier customers would pay for their own installation and would buy their plugs etc from the electrical contractor, they would also pay a LOT less than the free wiring customers per unit of power.

Somewhere I have an early installation book that shows bare cable laid into wooden channels, for posher installations these wooden channels could be provided with a cover! The U shaped channels were simply tacked along walls and ceiling. No mention of earthing whatsoever, as I recall.

[Mónico González]

Here are a nice example (Tomorrow will be again in use) of an Spanish "vitreous" porcelain base. It's a sturdy device designed for lifelong service (unless if you left it drop over the floor).
This is twenty or twenty-five years old, but despite a little rust layer over his contact screws, it remains as if it were brand new.
Note the difference between front and rear surfaces.
While the front side has a vitrified "glass-like" finish, the rear one are rough finished, showing a curious grid pattern, moulded over the porcelain surface, constituted by two crossed series of protruding and fine lines that forms a sort of squared mesh.
These bases were made by the Spanish "Sim?n" brand.
This kind of design was superseded some years ago by the new CE (European Union) homologated plug and base systems, althoug new plugs could be connected to these older base types without any problem, because the pin diameter (4 mm) and pin separation (19 mm) are actually the same, unless for German Schucko (laterally grounded) plugs and fittings.
Please, I would to know if old British bases and sockets were sometime of the same type and sizes as in continental Europe.

Best regards,
M. Gonz?lez.

[debook]

British fittings allways differed from the continental, although I would not be surprised to find some use of European types prior to standardisation. Since standardisation british connectors for power were mostly polarised.

Up until the 1960's 5amp plugs and sockets had small round pins and 15 amp large round pins, earlier there was at least one other 'standard size', they were mostly unfused. Mostly they are made from bakelite but more modern materials were used too. I am not sure exactly when the changeover to the fused rectangular pins occured but from then on only one size of plug was used.

Interior designers were, probably still do, sourcing old 5 amp plugs and sockets for using in room lighting circuits, the small size being less obtrusive.

The BC lamp socket is ubiquitous in the UK although a substantial and increasing percentage of lighting retailed since the 1970's uses ES sockets.

The standards were fairly strongly controlled on safety grounds and contintental systems were considered less safe. The rectangular pin sockets mostly contain a spring loaded cover for the live and neutral terminals that is operated by the longer earth pin of the plug. In Europe the terminals are uncovered and there are a selection of retrofitting sprung covers that are very awkward to use, but sold for child safety. I had no trouble as a child using a srewdriver to push down the springs so that I could poke wires into the socket - in this respect the UK variation is less safe as the sprung cover stop the loose wires from falling out. It is not uncommon in the UK to see hifi's and computers connected to a single socket without plugs due to this integrated 'clip'.