BULLETIN 336, XI. S. DEPARTMENT OF AGRICULTURE. 



Table II. — Annual and average mean, maximum, and minimum temperatures, by 

 months, at Washington, D. C. — Continued. 





1909 



1910 



1911 



1912 



1913 



Average. 



Month. 



03 



3 





.5 



i 



y 



03 



a 



a 



03 



03 



3 



.a 

 a 



03 





.a 



a 





03 



a 



B 



03 



03 







74.7 

 73.0 

 66.4 

 53.1 



96 

 96 



84 

 80 

 77 

 66 



53 

 53 

 42 

 31 

 29 

 8 



77.6 

 73.8 

 71.0 

 60.2 

 41.4 

 30.5 



95 

 90 

 94 

 90 

 66 

 62 



57 

 58 

 48 

 31 

 23 

 8 



78.7 

 76.6 

 70.4 

 57.2 

 42.8 

 41.0 



99 

 100 

 89 

 80 

 70 

 67 



56 

 54 

 46 

 38 

 22 

 22 



75.8 

 73.4 

 70.4 

 59.3 

 46.9 

 40.0 



94 

 92 



94 

 87 

 77 

 73 



60 



53 

 42 

 36 

 25 

 19 



77.6 

 74.2 

 67.4 

 58.8 

 47.8 

 40.4 



97 

 97 

 93 



77 

 76 

 66 



58 

 54 

 40 

 35 

 28 

 24 



76.4 

 73.9 

 69.0 

 56.7 

 45.6 

 36.4 



35.6 

 33.4 

 43.2 

 54.2 

 64.7 

 71. 8 



55.1 



95.-1 

 93.7 

 90.3 

 83.7 

 71.9 

 65.9 



65.5 

 62.7 

 77.9 

 85.2 

 90.4 

 95.0 



56 6 





54 5 



September 



42.9 



November 



50.8 



24.5 

 15 5 









1910 



1911 



1912 



1913 





L914 







33.7 

 34.7 

 51.2 



58 

 68 

 86 

 92 

 87 

 94 



96" 



11 



8 

 26 

 37 

 39 

 45 



38.2 

 37.0 

 41.0 

 51.2 

 70.0 

 73.0 



68 

 68 

 75 

 80 

 96 

 101 



ioi" 



15 

 21 

 14 

 26 

 37 

 56 



25.0 

 31.0 

 40.9 

 55.6 

 65.1 

 70.4 



54.6 



58 

 56 

 76 

 81 

 90 

 93 



ioo~ 



-13 



7 

 18 

 31 



41 

 45 



43.6 

 36.4 

 49.0 

 55.4 

 64.4 

 72.8 



57.3 



68 

 68 

 77 

 86 

 90 

 96 



"s6" 



24 

 13 

 17 

 32 



37 

 45 



38.6 

 30.1 

 29.4 

 53.5 

 67.0 

 75.9 



55.1 



72 

 59 

 75 

 86 

 95 

 98 



98 



7 

 -1 

 15 



28 

 41 

 56 



8 f- 



February 



8.5 

 19 ■> 





57 9 



28 8 



May 



61.5 

 69.7 



54.9 



38-3 

 49 8 







Annual: 



Mean 



Maximum . . 



55.4 









Minimum 



8 





8 





-13 





13 





-1 





































Table II shows that the highest average mean temperatures have 

 been recorded in July and the lowest average means in February. 

 The average mean temperature for the 10 crop years was 55.1° F. 

 The variation from this average has been slight, the warmest crop 

 year having an annual mean of 57.3° and the coolest 52.9°. During 

 the 10 years the absolute maximum has exceeded 100° F. only once, 

 and the absolute minimum has fallen below zero in only three years. 

 The lowest temperature recorded during the period was in January, 

 1912, —13° F. The annual mean temperatures at College Park are 

 almost invariably 1 degree lower than at Washington. 



NATURE OF THE EXPERIMENTS. 



The primary object in all the varietal tests at College Park and 

 Arlington Farm has been to determine the relative yielding; power of 

 the different varieties. Attempts have been made also to improve 

 the yield, quality of grain, and other important characters in some 

 of the leading varieties by both mass and pure-line selection. The 

 production of new varieties by hybridization also has been attempted. 

 The work done along these latter lines has been too extensive to per- 

 mit presentation within the limits of this bulletin. 



Nursery experiments in which each variety is grown in short rows 

 of uniform length, row space, and rate of seeding are also conducted, 

 in addition to the regular varietal tests in field plats. The usual pro- 

 cedure has been that if a new variety is especially promising in the" 

 nursery it is advanced to the field-plat tests as soon as sufficient seed 



