OF THE ATMOSPHERIC TEMPERATURE. 



171 





Calendar 



Correction. 



Corr'd 





Calendar 



Correction. 



Corr'd 





Month. 



I. 



II. 



Mean. 





Monlh. 



I. 



II. 



Mean. 





Mean. 











Mean. 









January 



26°. 46 



o°.oo 



o°.oo 



26°. 46 



July 



71°. 69 



-j-o°.o6 



+o°-o7 



7i°-76 



February- 



28.08 



-|-O.I2 



-)-O.I2 



28.20 



August 



70.24 



— 0.07 



— 0.07 



70.17 



March 



36-03 



+0.46 



+0-43 



36-47 



September 



62.49 



—0.18 



— 0.16 



62.32 



April 



46.96 



+0.44 



-t-o-47 



47.42 



October 



51.06 



—0.15 



— 0. 16 



50.90 



May 



57.28 



+0.41 



-1-0.42 



57-70 



November 



40.28 



— 0.14 — 0.1 1 



40.16 



June 



66.96 



+0.27 



-1-0.28 



67.24 



December 



30.42 



— 0.08 — 0.08 



30-34 









Uncorrected annual mean 48°. 996 













Correction -|- 0.099 













Corrected mean 49.095 







The monthly corrections, beginnmg with January and continuing in regular pro- 

 gression, for two extreme cases are given below, viz., for Key West, Flo., with an 

 annual range of about 14°. 7, for New Haven, Conn., with about 46°. 7 and for Fort 

 Snelling, Minn., with about 61°. 8. 





„ 



^ 



3 



„ 



Q 



Q 



Q 



Q 



g 



„ 



^ 



^ 



Key West 



.00 



+-04 



+-11 



+-14 



+ •13 



+ .09 



+ .02 



.01 



—.04 



-•o.S 



— .04 



—•03 



New Haven 



.00 



+.12 



+-44 



+ ■46 



+ .42 



+ .28 



+ -07 



— .07 



— -17 



— .16 



.12 



—.08 



Fort Snelling 



.00 



+.21 



+ .67 



+-63 +-47 



+ .28 



+ .04 



.12 



—.19 



—.19 



—.18 



.11 



Expressed in parts of the half of the annual range or nearly as a multiplier of 

 Bi, the correction to the mean temperature of the year derived from the mean 

 temperature of the calendar months, in order to obtain the true mean derived from 

 the daily means, has been determined for a number of stations as follows : — 



Locality. 

 Fort Snelling, Min. 

 Brunswick, Me. 

 St. Louis, Mo. 

 Fort Laramie, Wyo. 

 Albion Mines, Nov. Sco. 

 New Haven, Conn. 

 Toronto, Can. 

 Providence, R. L . 

 Marietta, Ohio 

 Austin, Tex. . 

 Charleston, S. C. . 

 Sitka, Alas. 

 San Diego, Cal. 

 Key West, Flo. 

 San Francisco, Cal. 



The factor seems to diminish with a diminishing 



oprox. Value of 





Half Range. 



Factor. 



30°. 9 Fah. 



0.0043 



24.2 



41 



24.1 



38 



23-7 



37 



23.6 



SO 



23-3 



44 



22.8 



45 



22.6 



44 



21.4 



43 



16.0 



34 



iS-9 



34 



12.3 



39 



9-5 



36 



7-3 



38 



4.9 



23 



ange, but is sufficiently constant 



and equal to 0.0043 for half ranges above 20°, and equal to 0.0036 for half ranges 

 below 20°. The San Francisco value is known to be exceptional. 



The effect or correction to the epochal angles, Cj O2 Cg, may be seen from the fol- 

 lowing selected expressions of typical stations: — 



