Two years ago the author read a short paper in which he gave the intensity of illumination required when direct lighting is used as compared with what is required when indirect lighting is employed. Experimental results were given based on the average obtained from 26 college seniors. The data showed that 2.8 ft. candles were desirable for reading by direct lighting and 4.0 ft. candles by indirect lighting, both being median value. Only artificial light was used.
Proceedings of the Iowa Academy of Science
©1924 Iowa Academy of Science, Inc.
"A Note on Daylight Requirement,"
Proceedings of the Iowa Academy of Science, 31(1), 387-388.
Available at: https://scholarworks.uni.edu/pias/vol31/iss1/133