.v/A- IV ILL1 AM SIKMKXS, J'.K.S. 235 



different aspect if natural sources of power, such as waterfalls, 

 can be rendered available within a short distance. The cost of 

 : will in such case be almost entirely saved, and that of 

 attendance greatly diminished, and it seems probable that under 

 such circumstances electro-horticulture may be carried out with 

 considerable advantage. 



In reply to questions that have been frequently asked regarding 

 the cost of maintaining an experimental electric light of 1,400 

 candle-power, such as I have used in these experiments, I may 

 state that the 3 horse-power Otto gas engine employed in driving 

 the dynamo machine consumes nearly 1)00 cubic feet of gas during 

 the night of twelve hours, or 75 cubic feet an hour, which, at 

 3s. Gd. per 1,000 cubic feet, represents with the carbons a cost of 

 .W. an hour. This, however, does not include superintendence or 

 incidental expenses, the amount of which must depend upon the 

 circumstances of each case. 



The experiments furnish proof that no particular skill is re- 

 quired in the management of the electrical apparatus, as the gas 

 engine, dynamo machine, and regulator have been under the sole 

 management of my head gardener, Mr. I). Buchanan, and of his 

 son, an assistant gardener. The regulator only requires the re- 

 placement of carbons every four or five hours, which period may 

 easily be extended to twelve hours, by a slight modification of the 

 lamp. 



I am led to the following conclusions as the result of my 

 experiments : 



1. That electric light is both efficacious in producing chloro- 

 phyll in the leaves of plants and in promoting growth. 



2. That a light-centre equal to 1,400 candles, placed at a dis- 

 tance of two metres from growing plants, appears to be equal in 

 effect to average daylight in February, but more economical effects 

 can be attained by more powerful light-centres. 



3. That carbonic acid, and the nitrogenous compounds gene- 

 rated in diminutive quantities in the electric arc produce no 

 sensible deleterious effects upon plants enclosed in the same space. 



4. That plants do not appear to require a period of rest during 

 the 24 hours of the day, but make increased and vigorous progress 

 if subjected during daytime to sunlight and during the night to 

 electric light. 



