or THE ATMOSPHERIC TEMPERATURE. 



197 



Day of 

 Month. 



Jan. 



Feb. 



Mar. 



Apr. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 













Marietta, Ohio. 













Resulting annual fluctuation from 



a series 



of 32, years, 1818- 



1859, or mean temperature 



of every day, derived from | 



the 6th order of successive 



means. 







































„ 





a 



^ 















I 



31.8 



31.3 



37-3 



47.7 



60.3 



65.6 



72.3 



72.3 



69.0 



58.6 



47.1 



37-1 



2 



31-4 



31.0 



36.6 



48.1 



60 



3 



66 



3 



71 



8 



72.1 



69 







58 



3 



47 



4 



36.8 



3 



31.0 



30.7 



36.4 



48.8 



60 



3 



66 



8 



71 



I 



72 



2 



68 



9 



57 



4 



47 



4 



36-4 



4 



30-9 



30.3 



36.8 



49-4 



60 



3 



67 







70 



8 



72 



3 



68 



9 



56 



3 



47 



2 



36.1 



S 



31. 1 



30.0 



37-9 



49- S 



60 



2 



67 



2 



71 



4 



72 



4 



68 



9 



55 



3 



46 



7 



35-8 



5 



31-5 



30.0 



39-2 



50.3 



60 



I 



67 



5 



72 



2 



72 



4 



68 



9 



55 







46 



3 



35-6 



7 



31-9 



30.3 



40.4 



50.9 



60 







68 







72 



9 



72 



4 



68 



8 



55 



2 



45 



9 



35-5 



S 



31-7 



30.7 



41.2 



51-3 



59 



8 



68 



4 



73 



2 



72 



5 



68 



7 



55 



4 



45 



4 



35-2 



9 



31-1 



31.2 



41.4 



51-5 



59 



7 



68 



7 



73 



2 



72 



6 



68 



2 



55 



5 



45 







34. 6 



10 



30-9 



31.6 



41.6 



52.0 



59 



9 



68 



8 



73 







72 



7 



67 



3 



55 







44 



8 



33-9 



u 



31.0 



32.0 



42.0 



52.5 



60 



2 



68 



9 



72 



9 



72 



8 



65 



9 



54 



2 



44 



5 



33-5 



12 



31.2 



32.5 



42.2 



52.6 



60 



6 



69 



I 



72 



8 



73 







64 



6 



53 



I 



43 



8 



33-5 



13 



31-9 



32.8 



42.1 



52.4 



60 



9 



69 



4 



72 



8 



73 



3 



64 







52 







42 



5 



33-6 



H 



32-7 



33.0 



41.8 



S1.9 



61 



I 



69 



6 



72 



7 



73 



5 



63 



8 



51 



2 



41 



4 



33-6 



IS 



33-2 



33.0 



41-5 



51.6 



61 



5 



69 



9 



72 



5 



73 



3 



63 



7 



51 



2 



41 



I 



33-3 



i6 



33-0 



.32.7 



41.4 



51.6 



61 



8 



70 



2 



72 



5 



72 



9 



63 



6 



51 



7 



41 



3 



32.6 



17 



32.4 



32.S 



41-3 



51-7 



61 



9 



70 



3 



72 



8 



72 



4 



63 



6 



52 







41 



5 



32.2 



i8 



31-9 



33.7 



41.1 



S2.0 



61 



7 



70 



3 



73 



2 



71 



9 



63 



7 



51 



7 



41 



3 



32.2 



19 



31-9 



35.1 



41. 1 



52.8 



61 



4 



70 



2 



73 



6 



71 



5 



P 



7 



50 



7 



40 



8 



32.2 



20 



31-9 



36.2 



41.4 



54-3 



61 



5 



70 



I 



73 



7 



71 



I 



63 



2 



49 



7 



40 



7 



31.8 



21 



31.6 



36.9 



42.0 



56. 1 



62 



I 



70 







73 



8 



70 



6 



62 



3 



49 



4 



41 







31.0 



22 



30.8 



36.9 



42.8 



57-3 



62 



9 



70 



I 



73 



9 



70 



I 



61 



3 



49 



3 



41 







30-4 



23 



30.3 



36.6 



43-6 



57.8 



63 



3 



70 



I 



74 







69 



8 



60 



8 



49 



2 



40 







30.6 



24 



30-3 



36.2 



44.4 



57-9 



63 



4 



70 



4 



74 



I 



69 



7 



60 



8 



48 



7 



38 



4 



31-3 



25 



30.9 



36.1 



45-3 



57-8 



63 



5 



70 



9 



74 







69 



6 



60 



7 



48 







36 



8 



32.0 



26 



31-4 



36.2 



46.0 



57-6 



63 



9 



71 



6 



74 







69 



5 



60 



3 



47 



5 



35 



8 



32.0 



27 



31.8 



36.5 



46.4 



57-5 



64 



5 



72 



2 



74 







69 



5 



59 



7 



47 







35 



7 



319 



28 



32.2 



37-1 



46-5 



58.1 



65 



2 



72 



5 



74 



I 



69 



4 



59 







46 



6 



36 



2 



32.0 



29 



32.6 



37.6 



46.7 



59-2 



65 



5 



72 



5 



74 



2 



69 



3 



58 



6 



46 



3 



36 



9 



32.2 



30 



32.6 





46.9 



60.0 



65 



4 



72 



4 



73 



8 



69 



2 



58 



6 



46 



3 



37 



2 



32-3 



31 



32.0 





47-3 





65-3 





73-0 



69.1 





46.8 





32.2 



Variability in the mean temperature of any one day, in a succession of years. 



The fact that the amount of departure of the observed temperature of any day 

 of the year from the normal vakie assigned to that day from a series of years, is 

 variable at different periods of the year may be verified at a glance by an examina- 

 tion of the accompanying diagram of the annual fluctuation showing the progression 

 of the temperature from day to day. The zigzag lines or irregularities are evidently 

 much greater in winter than in summer. 



To obtain a measure of this irregularity we deduce the probable error of each 

 normal, and thus secure the advantage of comparative numbers of the amount of 

 this irregularity, as well as a knowledge of the degree of reliability of our normal 

 temperatures. 



Let n = number of years from which the mean temperature of any one day is 

 deduced. 

 A = difference from this mean and any observed temperature. 

 e = probable error of a single value observed, or the probable amount of 



ordinary departure from the mean or normal value. 

 s = probable error of normal value ; then, with sufficient accuracy for our 

 purpose, 



2A ^ e 



, = and s = —j^- 



Vn(n — l) Vn 



e = 0.845 



