In message om, Henry
writes

On Fri, 27 Oct 2006 18:19:04 +0100, Paul Terry
wrote in :

Does anyone know what these lamps are for? The South Circular through
Putney and East Sheen is pretty much exactly on one of the incoming
Heathrow flight-paths ... but surely they wouldn't be some kind of
landing lights, as we are about 9 miles away from Heathrow.

Also streetlamps tend to be along roads, which tend to have bends...

The Upper Richmond Road (South Circular) going west is reasonably
straight for several miles after leaving Wandsworth - one of the
incoming Heathrow flightpaths follows it fairly closely.

how many of these lamps are there?

Difficult to say as the blue dome can only be seen from above - I can
see about ten from my loft window, but all the lamp posts on this
stretch of road (several hundred in all) could be similarly equipped.

Do air ambulances have designated landing spots - could it indicate
something like that?

I doubt it - there are plenty of open spaces in the area which would
form better landing sites.

The colour's weird too - the human eye isn't very sensitive to blue,
so (per Watt) it seems a bad choice for something to be seen from a
distance, or in fog...

I must admit, I'm baffled!
--
Paul Terry