1913] NICHOLS—SUMMER EVAPORATION INTENSITY 147 
weeks; and 5 weeks later a fourth cup was substituted for the one 
which at that time had been longest in operation. Distilled water 
was used in all cases. The majority of the instruments were Set 
up during the last week of May and continued in operation until 
September 14. At the end of the season the cups were returned 
to the writer and restandardized,5 the readings being then corrected 
in the usual manner,‘ and all results coordinated with those derived 
from standard cups. Except where for one reason or another 
particular cups were manifestly unreliable, the records of the two 
were averaged to obtain the accepted readings. 
In this way a practically complete set of weekly readings 
throughout the season has been tabulated for nearly every station. 
Such a series of figures brings out a number of interesting facts. It 
is found that for the state as a whole the maximum weekly rate of 
evaporation for the season occurred during the first week in July, 
when there was an average water loss from each cup of 211 cc. 
During this week the instruments at Hayden evaporated 2 56 cc., 
and at 5 other inland stations in the Lowland and Eastern High 
land the rate exceeded 225 cc., while at Niantic there was a loss. 
of but 144cc. At no time during the season did the amount evapo- 
rated during the recorded week at any of the stations in the Western 
Highland or in the Coastal Region amount to as much as 225 cc. 
The lowest rate of evaporation throughout the state was observed 
during the first week in September, when the average was 41 CC., 
the minimum being reached at Niantic (22 cc.). The mean weekly 
evaporation rates for the state as a whole, based on the averages of 
all the stations, were as follows: 
June 1-June 8 146cc. July 27-Aug. 3 121 Cc. 
ee 2 oe 8 Aug. 3-Aug. 10° 113 “ 
ia9 15- ce 22 124 “ ‘ 10- “e 17 108 <7 
“ 22- ee 153 is3 ae 17- “ 24 53 “ce 
sie y 6 au * “ 24- “ 31 125 “ 
2 y 6- oe 13 155 ce ce 31-Sept 7 41 ify 
ta. Oe TS sept. j- ~*~ 4 tq” 
“ 20- “ce 27 170 “cc 
5See Nicuots, G. E., A simple revolving table for standardizing porous cup 
atmometers. Bor. Gaz. 55:249~251. 1913. 
6 See Plant World 13:111-115. 1910. 
