SCIENTIFIC JOTTINGS IN EGYPT. 825 



the gulf. This wind is a cool one, but it occasionally veers 

 around to the south and becomes oppressively hot. In April and 

 May this south wind, called khamsin, blows unremittingly for 

 days together, scorching the traveler's skin and filling the orifices 

 in his head with a very fine dry dust. Khamsin is from an Ara- 

 bic word meaning fifty, so called from a mistaken notion that it 

 blows for a period of fifty days before the summer solstice. 



In the Nile Valley, north winds prevail during the heated pe- 

 riod of eight months, and southern winds during the rest of the 

 year ; these being in the opposite direction from the winds in the 

 region of the Red Sea. 



I witnessed three characteristic sand-storms at localities far 

 apart and under varied circumstances. On February 15th, when 

 riding a donkey through Thebes Nileward, a powerful west wind 

 arose in the afternoon, blowing before it fine dust from the Lib- 

 yan Desert. Words fail to describe the discomfort of such a sand- 

 storm ; the fine dust seems able to penetrate everything except 

 perhaps an unbroken egg, and it is quite impossible to escape 

 from it ; to prevent suffocation, I borrowed from a fellah a coarse 

 yet closely woven blue outer garment and wrapped my head up. 

 Donkeys did not seem to enjoy the phenomenon any better than 

 the Bedouins, and they shrank from its blast as well as the 

 travelers. After crossing to Luxor in a boat, we found the resi- 

 dents in the large hotel much inconvenienced by the pene- 

 trating dust, although the building is screened by a handsome 

 garden. 



My second experience was in Cairo itself. On March 6th a 

 northwest, and consequently a cool, wind blew dust from the ad- 

 joining desert into the city with such power as to obscure the usu- 

 ally brilliant sun during an entire day. Residents of Cairo said 

 that the sand-storm was the severest in twenty-five years, and of 

 an unusual character being accompanied by a low temperature 

 instead of the scorching khamsin. 



I experienced a third sand-storm in the desert of Sinai, on the 

 plain of El Markha ; it was accompanied by a scorching south 

 wind, and the drying effects on the skin and the capital orifices 

 produced greater discomfort than the suffocating dust and cut- 

 ting sand ; my party could do nothing but sit in silence on our 

 camels, facing the storm, and the poor animals forgot to snatch 

 at the tufts of scanty shrubs, as is their custom. In the evening 

 the fierce wind very nearly overturned our tents in spite of extra 

 stays, and at dinner every course was seasoned with the all-pene- 

 trating dust. The temperature at 7 P. m. was abnormally high, 

 84 ; just twenty-four hours later it fell to 53, the wind having 

 meanwhile veered around to the north, bringing with it heavy 

 mists. 



