WHOLE VOL. 



NOTES. EUROPE 45 



The Giljraltar pressure data arc therefore monthly and annual 

 means (expressed in inches of mercury) for the period 1852- 

 1920 reduced to 32° F. and Lat. 45°. 



Height of Barometer cistern 53 ft. above Mean Sea Level. 



Hours of Observation 7^, if. and 21^^ Greenwich Mean Time. 



These data have been computed directly from the original returns. 



Temi)erature data shown have been computed directly from the 

 original returns and are monthly and annual means in de- 

 grees Fahrenheit for the jieriod 1852-1920. 



Rainfall. 



From August-October 1855 and for December 1872 the original 



returns are missing. 

 Data are missing for the period September-November 1878 when 



the Observatory was under repair. 

 Up to 1874 readings from a gage exposed 25 ft. above the 

 ground were made in addition to those from the gage on the 

 ground. Data for April. June, September and October 1864 

 were interpolated using the readings from the 25 ft. gage 

 which during the period 1866-74 gave totals approximately 

 10 per cent less than the gage on the ground. 

 Rainfall data shown are monthly and annual totals, in inches, 

 for the period 1852-1920 computed directly from the original 

 returns. 

 From February 1852-March 1862 gage was read at 9.30 a. m. 

 From April 1862-June 1908 gage was read at 9 a. m. 

 After July i. 1908 readings were made at 7'^ Greenwich Mean 

 Time. 

 Temperature. 



From August-October 1855 the original returns are missmg. 



also for December 1872. 

 In April, May. Tune 1853 the maximum thermometer was un- 

 serviceable, in January 1857 the minimum thermometer was 

 broken. The minimum thermometer was also out of order 

 in October 1876. Data arc missing for September to Novem- 

 ber 1878 and also for December 1884. 

 The values shown from February 1852 to December 1903 are 

 deduced from i (maximum -f- minimum), these latter refer- 

 ring to periods of 24 hours ending at the hour of the morn- 

 ing observation. They have been corrected to 1(7'' +13^' + 

 2x21'') by means of correction A, which is based on data 

 for the years 191 1 to 1920. 



