202 Agkioultural Experiment Station, Ithaca, N. Y. 



Th.e extremity of the light couipartment was forty feet distant 

 fi-om the lamp, and the roof is so low that much of the light was 

 reflected, yet at this distance, where there was only diffused light, 

 the plants at a month after the light stai'ted were much better 

 than in the dark house. 



The expeiiment was repeated with second and third crops of 

 lettuce with similar results, and with se\eral vaaieties. Febru- 

 ary uimli, Simpson lettuce Avas transplanted upon bench 4, and 

 the customary increase under the light took place. Mai-ch twenty- 

 second, when the lettuce was neai-ly large enough for mai-ket, the 

 light was transferred to house B, and thereafter the poorer plants 

 received the light These poorer plants soon showed the effect 

 of the new conditions, and the time between the matmity of the 

 two crops was considerably lessened. 



Peiliaps the best LUusti'ation which we found of the influence 

 of the light upon lettuce was afforded by a ci*op upon bench 1, 

 into which radishes were also planted. The interception of the 

 light by the radish leaves had a most marked ett"ect upon the letr 

 tuce plants which stood behind them, the adjacent plants which 

 chanced to be exposed to the full light being much lai'ger. The 

 bench therefore presented a very uneven appeai-ance when the 

 radishes were removed, and the shadows fmm the radish leaves 

 could be traced in the lettuce. Similar results were observed 

 where the dense shade of a rafter lay across the plants. 



In this connection, I wish to call attention to the fact that W. 

 W. Kawson, at Ailington, neai* Boston, now uses the elecUic light, 

 in the commercial forcing of lettuce. Some of his methods are 

 described by the present writei- in the August number of American 

 G^ai'dening. The house shown in the cut is 33x370 feet, coveriug 

 neaiiy one-thii*d of an acre. Along the noiUi side of this house 

 are three 2,000-caiidle power lamps which ai'e imu all night. Mr. 

 Kawson calculates that he receives a gain of five days in a cix)p 

 of lettuce by the use df these lamps, and as he grows thi'ee crojjs 

 during the winter the total gain is over two weeks' of time. The 

 gain from one crop is estimated to pay the cost of running the 

 lights all winter. The effect of the light is said to be marked at 

 the distance of 100 feet 



