52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 79 



Height of the thermometers: After April i, 1883, ht = io.2 m. ; 

 after April i, 1886, 111 = 13.5 (thermometer screened) ; after 

 April I, 1910, hi — 2 m. (thermometer in shelter); after 

 April I, 1918, ht = 27.5 m. 



BRESLAU 

 Pressure. 



Hours: Means of pressure. 1881-1886 one third of mean ob- 

 served values at 6'\ 14^^ and 22'' ; 1887-1920 one third of 

 mean observed values at 7'\ 14'" and 2i'\ 

 Temperature. 



Hours: Means of temperature, 1851-1886 one third of mean ob- 

 served values at 6'\ 14'' and iz^"- ; 1887-1920 one fourth of 

 observed values at 7'\, 14'^ and twice the values at 2i'\ 

 Exposure of tJiermometers: The exposure of the thermometers 

 at the astronomical observatory remained unchanged from 

 1 85 1 tb 1920. 

 Errors: From 1870 to 1887 the temperature appears to be some- 

 what too low. 



FRANKFURT A. MAIN 

 Pressure. 



Hours: The means of pressure from 1881 to 1892 are from ob- 

 servations at 6^, 14'^ and 10'^ divided by 3: from 1893 

 to 1920 from observations at 7'\ 14^ and 21'' divided by 3. 

 Temperature. 



Hours: From January i, 1835 to March 31, 1853 the tempera- 

 ture means were |(9'^^- 15'^ -f- 22'"" -f minimum). From April 

 I, 1853 to December 31, 1892 they were ^ (6'' -|- 14^-1-22^') 

 and from 1893 to 1920 they were j(7'^-|- i4'''-|-2i'^-|-2i^'). 



Height of thermometer: The height of the thermometer above 

 ground from 1835 to December 31, 1887 was 2 m. From 

 January i, 1888 to January 31, 1899 ^^ was 3 m., and from 

 February i, 1899 ^o December 1920 it was 2 m. 



Exposure of thermometers: After January i, 1888 the ther- 

 mometer was in a screen. After February i, 1899 ^^ was in 

 a shelter of the English type. 



Site: On December i, 1907 the station which had been in the 

 same location since 1835 was removed to a new location in 

 the city. 



Errors: The temperature appears to be about 0.3° C. too high 

 from 1857 to 1861 and from 1899 to 1907. 



