. Cyclopedia of farm crops. Farm produce; Agriculture. RESPONSE OF PLANTS TO ARTIFICIAL LIGHTS 23 period of four or five j'ears. Rane, formerly Bailey's student, used the incandescent light. At first, Bailey employed a 2,000 candle-power un- screened arc lamp suspended inside his forcing-house, and this was kept running all night. He made his experiments in a 60 feet long and 20 feet wide, this being divided by a partition. In one part of the house, plants were exposed to an elec- tric light at night, in addition to the daylight which they received, while the plants in the other
. Cyclopedia of farm crops. Farm produce; Agriculture. RESPONSE OF PLANTS TO ARTIFICIAL LIGHTS 23 period of four or five j'ears. Rane, formerly Bailey's student, used the incandescent light. At first, Bailey employed a 2,000 candle-power un- screened arc lamp suspended inside his forcing-house, and this was kept running all night. He made his experiments in a 60 feet long and 20 feet wide, this being divided by a partition. In one part of the house, plants were exposed to an elec- tric light at night, in addition to the daylight which they received, while the plants in the other part of the house were grown under normal conditions, receiving daylight only. According to his experiments the general effect of the electric light was to hasten maturity, and the nearer the plants were to the light the greater was the accelera- tion, which was par- ticularly marked in the case of crops like endive, spinach, cress and lettuce. He noticed a ten- dency for the plants to run to seed, and the leaves which de- veloped near the light became small and curled. The amount of starch in the leaves of both the electric and the non-electric plants was the same, al- though the starch more than in the normal plants. Nitrogen, however, was the same in both cases, but more amide nitro- gen had been changed into other forms than in the normal plants, and those grown under an electric light were richer in albumenoids. Dwarf peas blossomed and fruited earlier but yielded only four- sevenths as many seeds as those under normal con-. Fig. 44. Lettuce of the same age and variety grown under normal conditions of sunlight (above) and with naked electric arc light running part of the night in addition (below), five weeks after planting in permanent quarters. (Bailey.) appeared to be more developed in those plants exposed to electric light. Lettuce plants within three feet of the lamp were killed outright soon after they came up, and the remaining plants were seriously'injured, develop
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