"Giant" 100W Crompton lamp

[Zelandeth]

Actually enquiring to see if anyone here has any info in behalf of someone on a vintage radio forum.

What they've got is an electrically very ordinary 100W incandescent lamp...aside from the fact that it's absolutely huge.  10.5 inches (265mm) long and 6.5 inches (160mm) in diameter.  Which really looks rather silly with a B22 base on it!

My initial though was that it could simply have been a manufacturing error, wouldn't be the first time I've encountered a lamp that was not its stated wattage, albeit never to this extent.  However, the B22 cap, lack of a heat reflective disc in the neck, and the bulb stamp disprove that.

This brings me to believe that it might possibly be a lamp that was created for display purposes - possibly to demonstrate different lamp shapes.

There is a numeric code "79" on the lamp, a date code possibly?

Would be nice if someone could shed a little further light on this!  There must be SOME reason for the guts of a garden variety 100W lamp to be stuffed into a P(S?)160 envelope!

[Tim]

Hi Z,

I'd guess this is just a decorative type bulb.  For example, I have a similarly large and clear globe shaped bulb (150w) installed in my dining room chandelier since this fixture was designed for such a bulb to be somewhat exposed. 

[James]

This is simply a decorative lamp made by Crompton, I can remember seeing them on sale during the mid 1980s.  It was sold under the brand name "La Lampe" and was pretty expensive for what it is!  In 1987 they were on sale at ?7 each, around ?13 by today's standards.  Within a year or two they disappeared, presumably due to the high price.  It is simply a 100W filament which they sealed into the PS-170 bulb which would normally be used for 1500W GLS lamps.