THE STUDY OF TROPICAL SUNLIGHT. 

 Table IV. — Tucson, Arizona. 



27 



Date. 



Decompo- 

 Bition for 

 one hour. 



Temper- 

 ature. 



Remarks. 



1910. 

 October 24 



12.0 

 7.7 

 10.5 

 13.4 

 13.2 

 12.9 

 11.1 



32 

 23 



30 

 28 

 30 

 29 



Thin clouds. 

 Overcast, sun 11 to 12. 

 Clear, slight cirrus. 

 Dust storm. 

 Very thin clouds. 

 Clear. 



October 25 



October 26 



October 27 - 



October 28 



October 29 



October 30 



11.5 



28.7 





13.4 



7.7 













Table V. — Washington, D. C. 



Months. 



Aver- 

 age. 



Maximum. 



Minimum. 



Mean 

 maximum. 



Mean 

 minimum. 



Remarks. 



Clear days. 



1910. 



9.91 

 11.19 

 10.37 

 11.38 

 12.91 

 9.18 

 8.01 



9.08 

 12.60 

 11.96 

 13.09 



12.70 

 15.60 

 15.75 

 19.14 

 16.66 

 15.33 

 11.11 



11.50 

 14.24 

 12.63 

 13.48 



6.54 

 1.70 

 1.85 

 3.83 

 4.37 

 2.66 

 3.50 



6.66 

 9.66 

 11.29 

 12.32 



11.55 

 12.80 

 12.75 

 13.49 

 15.05 

 11.55 

 9.85 



10.34 

 13.88 

 12.63 

 13.48 



7.18 

 7.19 

 6.81 

 8.37 

 10.16 

 6.35 

 6.49 



8.07 

 10.68 

 11.29 

 12.32 





5 out of 8. 

 10 out of 14. 

 8 out of 10. 

 10 out of 18. 

 14 out of 16. 

 4 out of 9. 

 : 8 out of 11. 



i 8 out of 9. 

 1 4 out of 5. 

 1 2 out of 2. 

 j 3 out of 3. 



! 



7 out of 7. 



July 





AufiTUSt 



September . . . 



October 



November 



December 



1911. 



January 



February 



March 



April 









Without tem- 

 perature- 

 coefficient. 





Average- - 

 May 





10.88 



14.37 



5.85 



12.48 



8.63 



With our solu- 

 tion. 



7.21 



8.21 



5.72 



7.92 



6.27 



