112 



DISCUSSION OF THE DAILY FLUCTUATION 



Van Rensselaer 

 liarb. <f = 78°.6 



Fort Kennedy. 

 <)>-= 72°. o 



Sitka (13 yrs.). 



Thunder Bay Isl. 



Toronto. 

 t = 43° 



Mohawk. 

 <f = 43°-0 



Amherst. 

 <f = 42°-4 



New Haven. 

 t = 4i°-3 



Frankford Arsen'l 

 <fi = 40°.o 



Philadelphia. 

 <}) = 40°.o 



Fort Morgan. 



<(>=30°.2 



Key West. 

 <)> = 24°.6 



0.0 

 +0.1 



+0.23 

 +0.06 



+0.5 

 +0.4 



+0.42 

 -fo.28 



0.0 

 0.0 



+0.5 

 +0.S 



+0-3 

 +0.2 



+0.14 

 — o. n 



4-0.6 



+0-3 



+0.03 

 •13 



+0.28 

 +0.14 



+0-52 

 +0.01 



+0.28 

 — 0.06 



+0.29 

 ■0.21 



+0.28 

 4-0.17 



0.0 

 0.0 



+O.S 

 -|-o. I 



4-0.4 



4-0. II 



+°-5 

 +0.1 



4-0.12 

 — 0.19 



+0-33 

 4-0.29 



+0-33 

 4-0.18 



4-0.2I 

 ■0.15 



+0-39 

 0.08 



-ho. 22 

 4-0.09 



0.0 

 — 0.1 



-0.21 

 -0.2S 



4-0.8 

 +O.S 



4-0.4 

 — 0.2 



4-0.44 

 0.12 



-I-0.6 



4-0.2 



4-0.14 

 -I-O.I6 



4-0.62 

 0.00 



4-0.30 

 0.19 



+0-37 

 — 0.07 



4-0.03 



-0.02 

 -0.29 



4-0.8, 

 +O.S 



4-0.7 

 0.0 



4-0.72 

 4-0.07 



4-0.6 

 4-0.1 



4-0.38 

 — 0.17 



4-0.81 

 4-0.04 



+0-13 

 4-0.09 



4-0.89 

 4-0.23 



4-0.36 

 ••23 



4-0.30 

 —0.25 



+0-59 

 4-0.23 



4-0.6 

 4-0.4 



4-0.09 

 —0.17 



4-0.7 

 +0.5 



4-0.7 

 0.0 



4-0.69 

 4-0.12 



-1-0.9 

 4-0.2 



4-0.72 

 •07 



4-0.28 

 -fo.14 



4-0.30 



4-0.88 

 -j-o. 10 



4-0.79 

 4-0.14 



4-0.67 

 4-0.20 



4-0. s 

 4-0.4 



4-0.24 

 —0.15 



4-0.9 

 +0-3 



4-0.50 

 4-0.24 



+°-93 

 4-0.20 



4-1. II 

 4-0.38 



4-1. 00 

 +0.09 



4-0.85 

 4-0.25 



+0-3 

 0.0 



-0.05 

 -0.40 



0.0 

 -0.2 



4-0.4 

 -j-o. 2 



-t-0.69 

 -j-o. 12 



-j-I.OI 



— 0.02 



+0-29 

 —0.05 



-j-o.! 



+0.83 

 4-0.2 1 



4-1.02 

 4-0. 1 1 



4-0.68 

 4-0.15 



4-0.5 

 4-0.2 



+0.21 



O. II 



4-0.4 



-j-o. 2 



+0-3 



-j-o. 2 



-ho. 2 

 4-0.2 



4-0.40 

 0.13 



4-0.27 



i.i6 



4-0.7 

 4-0.1 



+0-3 

 0.1 



4-0.48 

 •0-35 



+0-37 

 .12 



4-0.19 

 .07 



+O.S9 

 4-0.04 



4-0.64 

 4-0.07 



4-0.78 

 — 0.14 



+0.53 

 -ho. 04 



4-0.09 



4-0.4 

 0.0 



4-0.1 

 0.0 



4-0.27 

 0.04 



-j-0.4 

 0.0 



4-0.32 



+0-15 

 .10 



4-0.78 

 4-0.07 



+0-S3 



-1-0.65 



'•35 



4-0.40 

 — 0.19 



4-0.2 

 -ho. I 



-ho.09 



4-0.2I 

 4-0.03 



+0-3 



4-0.2 



4-0.29 

 4-0. lO 



4-0.21 

 -i-o-oS 



4-0.52 

 -ho. 12 



-f-o-45 

 —0.03 



-f-o-75 

 0.09 



-I-0-39 

 —0.03 



-|-°-3 

 -1-0.3 



4-0.10 

 — 0.06 



4-0.1 



0.1 



— O.I 



4-0.12 



— O.OI 



-t-o-3 

 4-0.2 



4-0.19 

 4-0.10 



4-0.09 

 —0.05 



-I-0-3I 

 4-0.03 



-i-0.34 

 4-0.01 



+0.34 



4-0.28 

 -j-o. 02 



4-0.1 

 4-0.1 



-0.09 

 -0.17 



4-0.29 

 4-0. iS 



-f°-3 

 4-0.1 



-i-0.3 

 0.0 



4-0.36 

 0.04 



-ho.52 

 4-0.15 



4-0.44 

 —0.05 



-f-0.55 

 4-0.24 



-ho-37 

 4-0.02 



4-0.52 



+0.37 

 4-0.27 



-ho. I 

 4-0.1 



-0.2S 

 -0.29 



4-0.24 

 4-0.08 



0.65 

 4-0. 1 1 



4-0.53 

 4-0.01 



4-0-59 



4-0.44 

 4-0. - 



-I-0.3 

 -ho. I 



-ho.oi 



With the exception of Key West, where the proximity of the gulf stream pro- 

 duces an anomaly, the combination 1 (7, 2, 9 (bis)) is superior to the simple mean 

 for the three hours, and, in general, the results at the different stations are suffi- 

 ciently accordant to permit monthly average values of differences to be taken ; omit- 

 ting, therefore, the first three stations and the last station, we find the following 

 mean values applicable to most localities in the United States between latitudes 30° 

 and 45° and east of the Mississippi. 



Table of average differences, in temperature, of the mean derived from the 

 observations at 7, 2, 9, also as deduced from 7, 2, 9 [Ms), from the true daily mean; 

 -|- in excess, — in defect of the true value. Expressed in degrees of the Fahren- 

 heit scale. 



Combination. 



d 



-Q 



IS 



a. 

 < 



S 







LO 

 < 



0. 







> 



p 





Hours: 7, 2, 9 



7,2,9{mJ 



-hO.''32 



4-0.09 



4-o.°26 

 4-0.06 



4-o°25 

 —0.05 



4-o°4S 

 4-0.06 



-ho.69 

 4-0.18 



4-o°79 

 4-0.16 



4-o°76 

 -ho. 10 



4-o.°6S 

 — 0.06 



4-0.42 

 —0.09 



4-o.°42 

 4-0.03 



4-o°26 

 4-0.01 



4-o°34 

 4-0.14 



4-o°47 

 !-^o.o5 



In order to make use of the values of this table, as corrections to means derived 

 from observations at these hours, the sign is to he reversed. 



