I'm currently scanning a large archive and occasionally find pictures of interesting ideas, experimental schemes and lost ideas which I think would be of interest here.

The first is from "Daylight by Night", a luxurious colour book issued by The British Commercial Gas Association to mark the International Congress on Illumination in 1931. It features many keynote gas installations of the day, all printed on high quality paper and illustrated with many art-deco flourishes.

Vanbrugh Park, Blackheath,London





All the best,
Simon

PS This was previously posted to FaceBook but I felt it would be nice to start a thread here. More to come...

Hmm, that's like an old fashioned version of what happens at Dutch roundabouts, except they use fluorescent or LED backlit fingerpost signs with a quad-bracket of lanterns.

That must have been quite a sight.

Fascinating. Keep them coming, Simon.

Although the photo-voltaic nature of the selenium cell was well known, its use was limited for road signs, street lighting etc. The delicate nature of the associated amplifier to actuate a relay (employing the use of a fragile valve or two) was pitched in direct battle against the heavy vibrations caused by road traffic.

Radiovisor discovered a new switching circuit in the early 1930s and used it for their light sensitive controls. (The selenium cell now formed part of a voltage divider which used to charge a capacitor which – when it reached a target voltage – would discharge into a neon tube and switch a relay). It was still fragile, but appeared rugged enough for road use. The entire county of Surrey used Radiovisor equipment for island refuges, ensuring the pillars and associated lamp were lit when the surrounding lighting levels were low.

Despite this improvement, street lighting mainly used other switching systems until the 1960s.

A friend of mine recently opened up an old cast-iron column base compartment which still stood in the middle of a traffic island. He thought it was just the remains of an old street lighting column. But he discovered an entire Radiovisor control unit inside – which had probably been there since the 1940s.

All the best,
Simon