METEOROLOGY. 



317 



METEOROLOGICAL OBSERVATIONS AND RESULTS. 



BY J. WIESSNER. 



1st. The daily results of mean temperature of the air in shade, as 

 )bserved on a farm in the District of Columbia. 



2d. The monthly results. 



3d. A trial adjustment, assuming that the mean motion of tem- 

 perature may be represented by the motion of an elastic ball jumping 

 ip and down. 



4th. A comparison of the Washington summer with the summers 

 it Naples, Rome, Constantinople, Petersburg, and Savannah. 



The probable error for the Washington series being very small, 

 shows that the observations were made carefully and in large num- 

 3er ; also, that the last summer was a very regular one. 



The figures in the former table for adjusting the daily observations 

 tiave the probable error dr 0°.3, so that ten years' further observa- 

 tions will make them correct to the last figure. 



Next, a table containing p for each day of observation. By 

 jsing the three tables and the simple formula ?„ = ^m + P ^^5 ^11 

 the observations now at the end of 1857, 4,500 in number, may be 

 recomputed and compared with the individual records, which will 

 ^ive an average probable error of a single observation and reduction, 

 = zb 1°.4. 



Mean temperature of the air in the shade of the District of Columbia. 



■ Thermometer broke. 



t New station and thermometer, east corner District of Columbia. 



