The economics of the increasing cost of living and the analysis of the relations of necessities, conveniences, and luxuries are too complex to be thoroughly discussed here. In fact, the most expert economists would disagree on many points. However, it is certain that the cost of living has steadily increased during the past century and it is reasonably certain that the standards of the present civilization are responsible for some if not all of the increase. Increased production is an anchor to the windward. It may drag and give way to some extent, but it will always oppose the course of the cost of living.
When the first industrial plant was lighted by gas, early in the nineteenth century, the aim was merely to reinforce daylight toward the end of the day. Continuous operation of industrial plants was not practised in those days, excepting in a very few cases where it was essential. To-day some industries operate continuously, but most of them do not. In the latter case the consumer pays more for the product because the percentage of fixed or overhead charge is greater. Investment in ground, buildings, and equipment exacts its toll continuously and it is obvious that three successive shifts producing three times as much as a single day shift, or as much as a trebled day shift, will produce the less costly product. In the former case the fixed charge is distributed over the production of continuous operation, but in the latter case the production of a single day shift assumes the entire burden. Of course, there are many factors which enter into such a consideration and an important one is the desirability of working at night. It is not the intention to touch upon the psychological and sociological aspects but merely to look coldly upon the facts pertaining to artificial light and production.
In the first place, it has been proved that in factories proper lighting as obtained by artificial means is generally more satisfactory than the natural lighting. Of course, a narrow building with windows on two sides or a one-story building with a saw-tooth roof of best design may be adequately illuminated by natural light, but these buildings are the exception and they will grow rarer as industrial districts become more congested. Artificial light may be controlled so that light of a satisfactory quality is properly directed and diffused.