24 



BULLETIN 700, U. S. DEPARTMEXT OF AGRICULTURE. 



orating instruments which might al^^o furnish data on sunshine 

 intensity, the evaporation data from the white and I)lack spherical 

 atmometers have been used in connection witli tlie plant studies. 



15 

 14 



13 



IZ 



Oak- Brush Type Aspen - Fir Spruce -Fir 



White Sphere 



.... Black Sphere 



__-, Difference 



■piG. 9. — Summation of evaporation from black and white spheres and the difference 

 between them. Record made during growth studies. Started late. 



BAROMETRIC PRESSURE. 



4227.6 





\ 

 \ 





\ 

 \ 

 \ 







\ > 



\ y 



\ y 



\ 



3512.5 





■\ 





2953.8 









X K y 



Z604.3 





\ 2285.6 \ 



y y 







\ 



\ 



y 



y 







\ 

 /56I.Z\^ 



• 





1273.4 











^-^ 



_^ 



966.9 





7(9A^ 



^^^-^^^ 













52 L 



Days 70 D 

 1 



ziys 65 L 



ays 



The barometric pressure was measured by aneroid barometers. The 

 instruments were standardized from time to time at the central sta- 

 tion, where the elevation and pressure were known. 



