237 



tlais time tlu-re were 20 nights in avIiIlU tin liglit did not rnn, and there had been hnt 

 84 hours of electric light, worth about $3.50. la order to compute the cost of grow- 

 ing lettuce by the aid of the electric light, it is necessary to know how f;ir thr 

 influence of the light will extend. This we do not know, bnl Mnj lamp exerted thi.s 

 influence tliroughont a house 20 by 30 feet, and the results were as well marked in the 

 most remote part as tliey were near the lamp. 



The results obtained from lettuce suggest many questions, all of whieli must Iw 

 answered by experiment. We need to know if there is any particular time in the 

 life of the lettuce plant when the light has a predominating influence ; if a nuld light 

 is as good as a strong one; if the failure of the light during the moonlight nights is 

 a serious drawback ; to what distance the influence of the light extends ; if the same 

 results can be obtained by hanging the lamp over the house instead of inside it, 

 and by that means ligliting several houses at once; if other plants can be protitably 

 forced by means of electric light. In all the.se directions, and many others, we are 

 ]ilanning experiments for the coming years. 



The influence of the light upon productiveness and color of flowers was found to 

 vary with different species and difterent colors within the same species. Several 

 named varieties of tulips gave interesting results. * * * When these came into 

 lull flower, it was found that in every case the colors were deeper and richer in the 

 light house; Init the colors lost their intensity after 4 or 5 days and were indis- 

 tinguishable from those in the dark house. The plants in the light compartment 

 liad lunger stems and larger leaves than the others; and there was a greater number 

 of floriferous plants in the light. The tulips were grown at a distance of 10 and 12 

 feet from the lamp. 



Verbena flowers near the light were iiniformly injured. * » * Scarlet, dark 

 red. blue, and pink flowers within 3 feet of the light soon turned to a grayish white, 

 and this discoloration was noticeable to a distance of 6 and 7 feet. The plants 

 bloomed somewhat earlier in the light house than in the other. 



A few fuchsias were grown in both houses. Those in the light house were about 

 8 feet from the lamp, and they flowered 3 days earlier than the others. The colors 

 were not changed. 



Heliotroijes of various-named varieties standing 9 and 10 feet from the lamp did 

 iR>t appear to be aff'ected in any way. 



White ageratums stood at 3 feet from the lamp. The flowers soon turned brown 

 and sere. Those in the dark house remained white three times as long. 



Chinese primulas at 7 feet fj-om the light were not afi'ected, but those 4 feet away, 

 especially the lilacs, were changed in color. The lilac was blea'ched out to pure 

 white wherever the light .struck squarely upon the flowers, but any portion of the 

 flower which chanced to be shaded by a leaf or another XJctal retained its color for 

 a time and then gradually became duller. * •■ * 



Petunias were much affected by the light. The plants were much taller and slen- 

 derer in the light, even at the farthest corners of the house, and they bloomed earlier 

 and more profusely. * * * White petunias were not changed in color by the 

 light, but purple ones quickly became blue, especially near the lamp. « * * 



Coleus plants of various colors were placed at different distances from the lamp 

 ^Nlarch 31. After 2 nights the plants within 3 feet of the lami) were much affected. 

 I'eds became yellow, browns turned green, greens lost their brightness, and dark 

 l>iu-ple became glossy black. [Plants farther away from the light changed color 

 more slowly.] 



[Observations upon the duration of flowers of various colors and species in both 

 houses are tabulated.] Perhaps the most noticeable feature of these figures is the 

 lack of uniformity in duration under similar conditions. Xeither the distance from 

 the lamp nor the hours of light received by the flower appears to determine the 

 duration. The longevity of the flower is probably determined more by the vigor 

 and general condition of the ]dant than by the variations in the amount of light, 

 although this subject is oni' which demands closer investigation. 



