Contributions in geographical exploration . Y LOW. Probably the most significant records available for estimatingthe conditions under which the plants grow, are those of thehygrothermograph and of the atmometers. The record of thehygrothermograph for a typical week, July 17-24, 1916, isreproduced herewith. In addition, the records of the ten weeks,including the best of the growing season, during which theinstrument was operated at Kodiak, ma^^ be this period temperatures above 70° F. were reachedonly five times, for an hour or two only in each case. Thehighest temperature was
Contributions in geographical exploration . Y LOW. Probably the most significant records available for estimatingthe conditions under which the plants grow, are those of thehygrothermograph and of the atmometers. The record of thehygrothermograph for a typical week, July 17-24, 1916, isreproduced herewith. In addition, the records of the ten weeks,including the best of the growing season, during which theinstrument was operated at Kodiak, ma^^ be this period temperatures above 70° F. were reachedonly five times, for an hour or two only in each case. Thehighest temperature was °. The lowest was 40°, buttemperatures below 45° were reached twenty-six timesand sometimes were held for a number of hours. The lowestrelative humidity recorded was 47%, and only on fifteen dayswas the humidity reduced to less than 00%• More significantis the fact that during twelve hundred and sixty hours or 75%of the period, the humidity stood above 80%. Inasmuch asthis record was taken in the open in an instrument shelter of. *?/&/ -^^ A//T/rt ^7y^3 pi^^^i_uoj -yuooa-^ Nov., 1918] Recovery of Vegetation at Kodiak 21 standard type, where humidity was at a minimum and evapora-tion high (see below), it is evident that there was small dangerof seedlings suffering from drought in the field. The evaporation data were taken by non-absorbing cylin-drical atmometers furnished by the Plant World was located in an open school yard beside the otherinstruments, a second in a dense growth of young sprucetrees near Vegetation Station 11, a third in an open gladeformerly occupied by a small bog (Vegetation Station 12), afourth on a steep mountain side in the Calamagrostis-Alnusassociation at an altitude of two hundred and fifty feet, (Vegeta-tion Station 28), and the fifth on the summit of Pillar Mountain,a bare wind-swept situation at an altitude of twelve hundredfeet (Vegetation Station 17, see page 26). The average dailyevaporation rates from these instruments, co
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