i6 
NEIL E. STEVENS 
efficiency for each day. The table is obviously the same as that given 
by the Livingstons (5, p. 366) except that it assumes 45° instead of 
40° to equal unity. Whenever the mean daily temperature was 
below 45° the efficiency was considered zero. The efficiency index of 
each locality for a year is the sum of the daily indices. 
Table VII gives the temperature efficiencies for the various localities 
studied and the percentage of each based on the temperature efficiency 
of Charlottesville as 100 percent. This table should be compared 
first of course with the table of temperature summations. As the 
figures of the efficiency index at Charlottesville approximately equal 
the first two figures of the temperature summation at that point a 
rough direct comparison is possible. In general, it is evident that the 
temperature efficiency indices fall off less rapidly in amount from 
Charlottesville northward than do the temperature summations. 
This is shown more strikingly by the percentages and as is indicated 
by the figures the curve of temperature efficiency follows the curve 
of growth more closely for the northern localities than does the curve 
of temperature summations. The former falls slightly less rapidly 
than does the growth curve; the latter somewhat more rapidly. The 
only serious exception is Wilmington which has higher temperature 
summation and efficiency indices than the other Maryland stations 
or even Washington, D. C, without a corresponding increase in 
amount of growth. This discrepancy the writer is wholly unable to 
explain. 
Table VII 
Temperature Efficiencies 
Locality 
Year Ending 
Efficiencies 
Percent 
Year Ending 
Efficiencies 
Percent 
Charlottesville, Va. . . . 
Apr. 20 
635 
IGG.G 
Fairfax, Va 
Washington, D. C. . . . 
Apr. 22 
594 
94 
July" 28 
574 
90 
Frederick, Md 
27 
586 
93 
Woodstock, Md 
27 
586 
92 
Aug. 9 
562 
'89' 
Van Bibber, Md 
May 13 
632 
99 
Aug. 10 
605 
95 
15 
481 
76 
68 
18 
463 
73 
Mohonk Lake, N. Y. . 
24 
435 
II 
421 
66 
17 
431 
68 
17 
421 
66 
Williamstown, Mass. . 
22 
396 
62 
16 
381 
60 
Concord, N. H 
18 
384 
60 
19 
371 
58 
When the extent of the territory covered and the necessarily ap- 
proximate nature of the data and their calculation are considered the 
