OF GIBRALTAR. 23 



in July, for twenty-five years, there fell no rain at all ; 

 however, there have been a few instances, within 

 later years, of slight drizzling rain having fallen in 

 the month of July. 



The next subject to which I shall advert is the 

 temperature of Gibraltar. 



The temperature of an almost isolated place like 

 Gibraltar, exposed to so many physical agents, both 

 by land and sea, must naturally be expected to vary 

 from year to year. The average mean temperature 

 is stated by writers to be 72 Fahr. The annual mean 

 maximum 74 F., and the mean minimum 64 F., 

 but these results are not obtained from observations 

 of the real maximum and minimum of each twenty-four 

 hours; but the maxima of tables hitherto given are 

 from observations made at 3 P. M., and the minima 

 are from observations at 9 A. M. ; therefore it follows 

 that these statements are not quite correct, though 

 they afford a close approximation to truth. Soon after 

 my arrival in Gibraltar in the year 1843, I kept a 

 register of the observations made from Six's ther- 

 mometer, the results of which I found to vary conside- 

 rably from those given by former observers, and con- 

 sequently my Meteorological Reports, which were 

 published in the form of monthly abstracts in the 

 ' Gibraltar Chronicle,' have been adopted by the 

 piincipal medical officer, in his Medical Statistical 

 Reports to the Director-General of the Army Me- 

 dical Department. The following are the results 

 of observations made from May 1, 1844, to 

 March 31, 1845. 



