EAINFALL. ' 333 



had turned southwards, and was now travelling over the desert away from us, I 

 earnestly hoped, to expend itself in space before meeting with any unfortunate 

 victims. Inexpressibly thankful was I as we entered the town, for I could not 

 but feel that it had perhaps been a race for life. It was now over and we were 

 safe ; but it was several hours, or I may more truly say days, before the effect on 

 my overstrung nerves passed entirely away." * 



On an average, northern breezes are six times more frequent at Cairo than 

 those from the south. But as we ascend the Nile and approach the equatorial 

 regions the equilibrium tends to be established between the conflicting currents, 

 and in Nubia the northern or winter are about fairly balanced with the southern 

 or summer winds. 



Rainfall. 



The region of the Egyptian delta is comprised within the Mediterranean 

 climatic zone. Winter and summer here succeed each other as in Southern 

 Europe, the only difference being that the intermediate seasons of spring and 

 autumn are reduced to much narrower limits. t The Egyptian summer, during 

 which the Nile waters rise and spread over the land, is accompanied by the 

 clearest skies ; yet the atmosphere is then heavily charged with moisture, often 

 almost to the point of saturation. On the Red Sea coast especially, the traveller 

 finds himself at times enveloped as in a vapour bath. 



Winter is the rainy season, but it is seldom attended by much humidity, 

 although in the lower delta the rainfall often suffices to interrupt the commxmica- 

 tions. The banks of the canals, here the only highways, are changed by the 

 slightest showers into quagmires of treacherous and slippery mud. Even in 

 Alexandria, lying as it does within the influence of the moisture-bearing clouds 

 from the Mediterranean, the mean annual rainfall is only 7 inches according to 

 Russegger, or 8 inches according to more recent observers ; that is to say, one-third 

 of the quantity received by Paris, and one- fifth of the average for the whole of 

 France.* At Cairo, where the marine vapours arrive already deprived of much 

 of their humidity, the mean discharge is much less, amounting to no more than 

 about I3 inch, or the fiftieth part of the discharge at Cherra-Ponji in British 

 India. 



The ancient Egyptians called themselves the inhabitants of the "Pure Region." 

 Nevertheless the sky is overcast at Cairo for over three months in the year, and 

 at times the downpours have been heavy enough to flood the streets. In 1824, 

 and again in 1845, several houses were destroj-ed by these sudden freshets. In 

 -the Arabian and Libyan deserts south of the delta, the rains are still lighter, 

 although not altogether unknown, as is so often asserted. Tremendous discharges 



* " Wanderings in the Sudan," vol. ii., p. 250 



t Mean temperature of Egypt . . . Alexandria, 08° F. 



„ ., in August (hottest month) „ 79° F. 



„ „ in January (coldest month) ,. .54" F. 



Highest recorded „ 111° F. 



X Mean annual rainfall at Alexandria Irom 1873 to 1881, 8-.5 inches. 



