190 



NINETEENTH REPORT. 



Figure 7. Curves: to sliow daily readings of the "solar radiation" thermometer 

 (dotted line) ; plant thermometer readings at mid-day (in solid black) ; the 

 i?4-hour elongation of four ])lants, in millimeters (dot and dash). Readings were 

 made at 3 p. m. daily. 



O'^ww^ mtoc^coo^o 



Figure b. Curves: to show the total growth (elongation) of four plants for the 

 24-hour periods ending at 3 p. m. daily (dot and dash) ; the maximum tempera- 

 ture of the air (in solid black) ; the mean temperature of the air (dotted line, B) ; 

 and the soil temperature (dotted line, A). 



