The cost of daylight

Advancement in the production and use of artificial light can be emphasized in no better way than by the increasing tendency to depend upon it even in the daytime. A score of years ago artificial light was still a poor competitor with daylight. It was considered to be merely a feeble substitute by means of which the hours of industry or of recreation could be extended after a fashion. Today artificial light compares favorably with daylight in efficiency, does not always cost more and has many advantages in controllability and dependability.