AIR TEMPERATURE 15 
Table 17. Mean hourly values of air temperature in degrees centigrade for groups, 
Carnegie, 1928-29--Concluded 
(Corrected for noncyclic change) 
Local mean hours 
ee 
I 10570) 1050" 10877 ~ 10:60 ~~ 10255 
U 18.39 18.54 18.59 18.51 18.62 
Ill 27.27 27.24 27.21 26.95 26.61 
IV 28.44 28.25 27.80 27.52 27.21 
Vv 29.04 28.79 28.52 27.94 27.87 
VI 25.77 25.73 25.78 25.52 25.27 
Vil 
3} 22.08 21.81 21.65 21.46 21.24 
b 27.02 26.77 26.49 26.40 26.28 
vul 17-93 sD N82 4748 
Ix 21.80 21.53 21.16 20.85 20.61 
x 24.95 24.69 24.35 24.29 24.05 
XI 28.59 28.29 28.05 28.02 27.87 
XII Zot eAatO)  20tG Aino  20d0 
xi 
ay 21.12 21.09 20.96 20.86 20.60 
b 16.06 15.96 15.90 15.85 15.83 
XIV 10.16 10.07 9.99 9.85 9.72 
XV, 15.34 15.42 15.32 15.29 15.27 
XVI 18.97 19.06 19.00 18.87 18.49 
XVII 
{2 23.83 23.81 23.67 23.43 23.05 
b 25.92 25.68 25.08 25.09 24.79 
(c 22.97 23.07 22.99 22.89 22.57 
XVIII 28.03 27.95 27.78 27.51 27.20 

10.24 10.03 9.93 9.87 9.72 10.06 
18.21 USS ial eS8 lee O0) 17-90 
26.25 26.10 25.99 26.07 25.95 26.33 
27.05 26.87 26.84 26.79 26.65 27.28 
27.74 27.71 27.70 27.70 27.90 28.16 
25.11 25.11 25.15 25.13 25.18 25.29 
21.11 21.04 20.96 20.96 20.89 21.30 
26.04 25.98 25.89 25.86 25.84 26.13 
17.33 17.22 17.20 17.06 16.99 17.40 
20.22 19.89 19.80 19.71 19.65 20.31 
23.76 23.69 23.65 23.55 23.51 23.96 
27.59 27.55 27.58 27.43 27.42 27.85 
DieGl  2ieOd)  2eGle ston Glee waletit eleds 
20.31 20.24 20.19 20.25 20.33 20.55 
15.67 15.54 15.39 15.43 15.60 15.67 
9.64 9.67 9.71 9.71 9.81 9.80 
15.04 14.82 14.60 14.44 14.42 14.65 
18.36 18.25 18.23 18.14 18.06 18.29 
22.74 22.63 22.63 22.66 22.64 22.90 
24.69 24.71 24.72 24.70 24.57 25.08 
22.65 22.66 22.62 22.64 22.79 22.79 
27.11 27.03 27.01 26.96 26.89 27.28 

Days omitted as follows: (a) Aug. 25, 26; (b) Dec. 3-12; (c) Dec. 25, 26; (d) Mar. 4, 13-20, 26: 
May 6 
(5) Det 18, 
Correcting for 
Excessive Daytime Deck Temperatures 
An examination of the original Hartmann and Braun 
records indicates a diurnal variation in the apparent 
lapse rate between deck and crosstrees (masthead rec- 
ords were too incomplete for use). As has been suggest- 
ed, this diurnal variation was no doubt due to the heating 
of the lower deck thermometer during daylight hours, 
and from this variation it was possible to correct the 
mean deck temperatures to values less affected by radi- 
ation and absorption. Likewise a diurnal variation in 
differences between temperatures recorded by the Hart- 
mann and Braun dry-bulb at the crosstrees and the 
Negretti-Zambra dry-bulb in the deck screen was dis- 
covered. The amplitude of this latter variation, how- 
ever, was not as great as the differences between the 
two Hartmann and Braun thermometers, presumably be- 
cause the Negretti-Zambra instrument was better venti- 
lated. 
It has seemed justifiable to use curves of these dif- 
ferences for computing corrections for the daytime 
hourly mean air temperatures recorded by the Negretti- 
Zambra dry-bulb. The curve of differences during day- 
light hours between the Negretti-Zambra dry-bulb tem- 
peratures on deck and the Hartmann and Braun dry-bulb 
temperatures at the crosstrees (means for groups) has 
been applied as a correction to the mean values of air 
temperature. The resulting mean hourly values for 
GroupsI to XIIIb, corrected for noncyclic change, are 
given in table 18. Data from the Hartmann and Braun 
instruments were not complete enough to make these 

11, 20-25; (f) June 8-24; (g) Two dates July 14 on crossing 180° meridian; (h) Sep. 20-Oct. 2; 
corrections for the remaining groups. 
To illustrate the result of applying such corrections, 
two Groups, VIla and IX, have been selected and the cor- 
rected and uncorrected data plotted in figure 13. The 
dotted line represents mean air temperature as read 
from the Negretti-Zambra dry-bulb and corrected from 
the Assmann readings. The dashed line represents the 
Negretti-Zambra data corrected by means of the differ- 
ences between the Hartmann and Braun deck and cross- 
trees temperatures. The unbroken line represents the 
air temperatures corrected for the mean differences be- 
tween the crosstrees temperatures (Hartmann and Braun) 
and the deck temperatures (Negretti-Zambra). This has 
been accepted as the most acc ‘rate value which can be 
obtained from the available data. These corrected mean 
values will be used in many of the air-temperature an- 
alyses. 
DISCUSSION 
General Remarks 
The importance of maritime meteorological results 
increases with the number of observations andthe length 
of the period during which such observations are made. 
The present results of temperature observations on 
board the Carnegie, therefore, cannot claim to have a 
value comparable with those of continental and island 
meteorological observatories, since the area explored 
by the Expedition was large, the duration of stay in any 
given region short, and the climate, particularly with 
reference to air temperature, heterogeneous. 
