I keep buying odd books in charity shops, odd because I would rarely choose to buy them from new and usually a subject matter that would not be first choice either. However, many have been fascinating and informative.
The latest is Spitfire by Jeffrey Quill (ISBN 0-09-937020-4), Quill was a test pilot in the late 1930s who tested and helped refine various aircraft. In the book he mentions landing in the dark on a couple of occasions (pages 71 & 128) where he was aided by "Chance lights", in the index they are referenced as Chance floodlights.
I wondered if they were floodlights that illuminated the (grass) landing field or were they the sort of lights that guide an aircraft towards the start of a runway?