8o MANAGEMENT OF THE FORCING-HOUSE. 



made of naphtha and white lead may be put upon the 

 glass. This is removed with difficulty. For forcing-houses, 

 which only infrequently need shading, an ordinarily slaked- 

 lime-and-water whitewash, which can be both applied and 

 washed off by means of a spray pump, is the best covering. 

 A still less durable wash is made of flour and water. 



THE ELECTRIC LIGHT FOR FORCING-HOUSES. 



Can the electric light stand for sunlight? Can it be 

 profitably used at night and in dull weather to hasten the 

 growth of plants ? These questions have received greater 

 attention in the United States than elsewhere in the 

 world. Experiments have been made at the Cornell 

 Experiment Station,* the West Virginia Station, f and 

 by W. VV. Rawson, an extensive vegetable forcer at Bos- 

 ton. It is found that the electric light, both the arc and 

 the incandescent, can be advantageously used upon let- 

 tuce to piece out the sunlight in midwinter. In various 

 florists' plants it also produces earlier bloom. It is usu- 

 ally injurious, or has only negative results, upon radishes, 

 peas, carrots, beets, spinach and cauliflowers. 



Upon lettuce, the value of the electric light in hasten- 

 ing maturity is emphatic. Mr. Rawson saves about a 

 week upon each of his three winter crops by the use of 

 three ordinary street lamps hung over a house 370 ft. 

 long and 33 ft. wide. 



At Cornell, the results upon lettuce have been marked 

 in many tests, and the gains in maturity have been as 

 much as two weeks. It is found in every instance that the 

 naked arc light that is, a light without a globe hung 



* Bailey, Bulletins 30 (Au K . 1891), 42 (Sept. 1892), 55 (July 1893); a!o, 

 "Electricity and Plant-Growing," in Trans. Mass. Hort. Soc'y, 1894. 

 Experiments with electric currents upon plants, by Clarence D. Walker, 

 will be found in Bulletins 16 (1892) and 23 (i8oj) of the Mass. Hatch 

 Exp. Sta. 



tRane, " Electro- Horticulture with the Incandescent Lamp," Bulle- 

 tin 37 (July. 1894). 



