Light reflectors on top of buildings?

[hammy1]

I am wondering if anyone on this site could possibly help me. I watched a show about a month ago on the History Channel called Modern Marvels. It had a segment on skyscrapers (I believe). At any rate, what sparked my interest was that I noticed on top of one of these buildings was a reflector type device which could be positioned to actually reflect sunlight onto the street where the structures had shaded entire blocks. This made an artificial sunny street, where otherwise would be shade. Does anyone know what I am talking about? I am interested in finding more about this! I would like to know what the correct name of the item I am describing is called and where I might be able to do a bit more research on it. I thank you greatly for your time.

[JM Bastin]

no personal answer for the name of the item described in your post but do have glance to the inside view of the former HK China Shanghai Bank office building so well designed (in 1986?) by FOSTER architects:
<http://www.juergen-reichmann.de/asien/vrc/hongkong.html>
you 'll see on top of the huge 15 levels atrium a very interesting computer driven solar device so as to enlight the inside void till the groung floor:nice isn't.... let us have a thread on this future developpement of solar energy on a large scale in our modern cities.