CONTROLLED ENVIRONMENTAL CONDITIONS 



Figure 124. A, End view photograph of the new type greenhouse showing the refrig- 

 erator type of door and the method of supporting the house on cement pillars. C, Night 



view through the storm sash. B, Plants inside the house on December 29. 

 plants taken February 9, or 42 days later. 



D, Same 



available space, a portion of an ordinary greenhouse was equipped with 

 lamps to correspond to the insulated house, and these lights were turned 

 on and off by the insulated house thermostat. Dry weight production and 

 flowering were greatly increased in both lighted houses as compared ^\'ith 

 the controls \vithout additional light, but dry weight production was less 

 in the heated insulated house than in the ordinary greenhouse Avith the 



