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that electric light had practically the same effect as sunlight in 

 the production of chlorophyl, he considered that it was quite 

 reasonable to suppose that it might also act like the sun in ripen- 

 ing fruit and producing sugar. To test this he placed several 

 pots of strawberry plants in two groups, one of which was ex- 

 posed to daylight only, the other to solar light during the day 

 and electric light at night. Both sets of plants were kept at a 

 temperature of from 65 to 70 Farenheit under glass. 



The plants, at the commencement of the experiment were some 

 in bloom, others had the fruit just beginning to set. At the end 

 of a week the fruit on the plants exposed to the electric light had 

 swelled considerably more than the control ones, and some of the 

 fruit showed signs of ripening. For two nights the lamp was not 

 on, but when resumed, progress was very remarkable, in four days 

 the fruit was ripe and of a rich colour, while the plants exposed to 

 daylight only were scarcely coloured at all. He also found that 

 with melons reared under the electric light, the fruit set better, 

 ripening was accelerated and the flavour distinctly improved. 



Barley and oats germinated under the lamp, made rapid growth, 

 but did not come to maturity ; the same variety of seeds, however, 

 were sown in the open in January, in a plot over which the arc 

 light was installed ; they germinated slowly at first, owing to frost 

 and snow on the ground, but as soon as the weather became 

 milder developed very quickly and bore ripe grain by the end of 

 June. Siemens observed, during a night of hoar frost, " that 

 though the temperature on the ground did not differ materially 

 within the range of the electric light and beyond it, the radiant 

 effect of the light entirely prevented frost within its range," he 

 therefore suggested that the application of electric light in front 

 of fruit walls, in orchards and kitchen gardens, would be a useful 

 means of saving fruit buds at the time of setting. Of course the 

 question is, would the cost of doing so repay the fruit grower ? 

 In some districts where electric mains from large towns extend 

 out to the suburbs and the Board of Trade price per unit of current 

 does not exceed twopence or threepence, it might quite well be 

 done with profit. Lamps would not be in use in the greenhouses 

 at the time when late spring frosts are experienced, so might 

 easily be temporarily erected outside and incalculable loss be 

 saved in crops of peach plums and other stone fruits. 



In these experiments of Sir William Siemens the light was kept 

 on all night, thus extending daylight into twenty-four hours, 

 which is contrary to the accepted opinion that plants require a 

 period of rest for their normal development. In order to test 

 whether continuous light had had any injurious effect on their 

 reproductive powers he sowed some of the peas matured under 

 the arc light which germinated in a few days, and showed every 

 promise of vigorous growth. 



