Recently Hayden and Steinmetz experimented with a plot of ground 5 feet by 9 feet, over which were hung five 500-watt gas-filled tungsten lamps 3 feet above the ground and 17 inches apart.  The lamps were equipped with reflectors and the resulting illumination was 700 foot-candles.  This is an extremely high intensity of artificial illumination and is comparable with daylight in greenhouses.  The only seeds planted were those of string beans and two beds were carried through to maturity, one lighted by daylight only and the other by daylight and artificial light, the latter being in operation twenty-fours hours per day.  The plants under the additional artificial light grew more rapidly than the others, and of the various records kept the gain in time was in all cases about 50 per cent.  From the standpoint of profitableness the artificial lighting was not justified.  However, there are several points to be brought out before considering this conclusion too seriously.  First, it appears unwise to use the artificial light during the day; second, it appears possible that a few hours of artificial light in the evening would suffice for considerable forcing; third, it is possible that a much lower intensity of artificial light might be more effective per lumen than the great intensity used; fourth, it is quite possible that some other efficient light-source may be more effective in forcing the growth of plants.  These and many other factors must be carefully determined before judgment can be passed on the efficacy of artificial light in reducing the cost of living in this direction.  Certainly, artificial light has been shown to increase the growth of plants and it appears probable that future generations at least will find it profitable to use the efficient light-producers of the coming ages in this manner.

Many other instances could be cited in which artificial light is very closely associated with the cost of living.  Overseas shipment of fruit from the Canadian Northwest is responsible for a decided innovation in fruit-picking.  In searching for a cause of rotting during shipment it was finally concluded that the temperature at the time of picking was the controlling factor.  As a consequence, daytime was considered undesirable for picking and an electric company supplied electric lighting for the orchards in order that the picking might be done during the cool of night.  This change is said to have remedied the situation.  Cases of threshing and other agricultural operations being carried on at night are becoming more numerous.  These are just the beginnings of artificial light in a new field or in a new relation to civilization.  Its economic value has been demonstrated in the ordinary fields of lighting and these new applications are merely the initial skirmishes which precede the conquest of new territory.  The modern illuminants have been developed so recently that the new possibilities have not yet been established.  However, artificial light is already a factor on the side of the people in the struggle against the increasing cost of living, and its future in this direction is still more promising.