On Saturday 3 April 1993, a symposium was held under the title of "Urban sky glow, a worry for astronomy". The organizer of the symposium was the Technical Committee TC 4.21 on "Interference by Light of Astronomical Observations". This TC works under Division 4 (Lighting and Signalling for Transport) of the CIE ( Commission Internationale de l'Eclairage). The symposium was held at the Royal Observatory, Blackford Hill, Edinburgh, Scotland, in conjunction with a meeting of CIE Division 5 and with the LuxEuropa Conference. The programme included the following presentations by international experts on astronomy, lighting architecture, lighting engineering and instrumentation:

•Interference by light of astronomical observations (Dr. A. Schreuder; earlier presentation)
•Astronomy as an endangered science (Dr. P. Murdin)
• Obtrusive light and sky glow: is it all gloom? ( Dr. A. Fisher)
•A global network observation of night sky brightness in Japan: methods and results (H. Kosai, S. Isobe, Y. Nakayama)
•The Canary Islands experience (J D Castro; presented during the TC meeting)
•Sky glow conscious lighting design (N. Pollard)
•The Edinburgh Lighting Vision (D Brennan)

The publication contains 46 pages, 15 figures and 8 tables.