As I mentioned in the Newbie introduction section, I found a couple of very old projector lamps recently and was immediately hooked on the beauty and complexity of the lit filaments so decided to collect old lamps, from a starting point of no knowledge at all.

The collection started yesterday with this lovely large bulb, found hidden away on a top shelf in an old vintage /antique warehouse at the back of an industrial estate in Lincoln, UK.  I got it for £10 and was very happy, as you can see in the photograph.

I've tried to educate myself about it with searches online but still have a long way to go, so any further information about it would be appreciated.
 
The photos will tell you more than I can, but here goes with what I have so far. The cap is 40mm wide so it's an ES40. The total height of the lamp is around 230mm, with the glass part around 180mm.
It's 240V and 300W so presumably with the correct fitting I can plug this in and it should light up!
The transparent "shield" near the base it to protect against heat.

Now the questions:

1) What's the actual name of it, or its type? I haven't been able to find anything online exactly like it. The number on the top of the bulb is hard to read. The 62 is clear but not the final number, if it is a number. I though 0 but searching for Mazda 620  produced nothing.

2) How old might it be?  I read that The Mazda name was withdrawn in 1946 so I thought it must be earlier than that but I see other Mazda bulbs online which seem to be much later than '46, so maybe I'm wrong on that.

3) What might it have been used for? I see other large ES40 examples online and they are described as being for "Industrial use" but nothing more specific than that.

4) There's a covering or sheath of some kind running up the centre from the cap. I wonder what job that does.

Thank you!

The date code is definitely 62, if there's anything following it I can't make it out. In any case, 62 comes back as February 1971, 1979 or 1987, but I don't know which, I'm not too well up on incandescent lamps, more into discharge lamps but I'm sure someone here will be able to help.

By the way, the cap designation is either GES (Goliath Edison Screw) or as is more usual these days, E40.

This lamp would have been used for general lighting, most probably in industrial situations.

Nice photo, by the way  

Oh, one last thing - you'll get more replies if you post the photos in the gallery rather than here.

Great, thanks for that. I'll post a picture on the gallery if/when I get it lit up   I see you can buy an E40 to E27 adapter for just a pound or 2.

Great, thanks for that. I'll post a picture on the gallery if/when I get it lit up   I see you can buy an E40 to E27 adapter for just a pound or 2.

Just post the pictures you've already got again, it's not a problem. Be careful of some of the el-cheapo adaptors, a lot of them are not all that well made. I would suggest getting a few ceramic E40 holders, I get mine from here.

Ok, will do!

So a USA Mazda lamp can be later than 1946, but a UK Mazda is pre-1946, if I've got that right. Thanks!

The Mazda brand was introduced by General Electric of USA in 1909, to denote a particular kind of tungsten lamp.  GE licensed the patents of that lamp to its competitors and they also used the Mazda brand for such lamps.  In 1945 the use of the Mazda brand was banned in America under the antitrust laws.

GE operated many subsidiaries around the world, such as British Thomson-Houston in the UK, and French Thomson-Houston in France.  These international subsidiary companies also had the rights to use the GE patents and Mazda brand, and eventually the Mazda name became a more powerful brand than the manufacturers themselves.  It therefore took over as the company name in some countries.  Following the antitrust lawsuits after WW2 GE was also forced to relinquish its monopolistic shareholding of the international companies, but they were permitted to continue using the Mazda brand since it had become the name of some individual companies.  In the UK it continued until around 1995, and in France until around 2005. 

The sheath over one of the leadwires is Vidaflex glass fibre sleeving.  It contains a fuse wire, and the purpose is to prevent the glass shattering if the fuse should melt when the lamp fails.