114 TKANSACTIONS OF THE [FEB. 24, 



drop impressions. The line of the now arid water-course was 

 often bordered by scanty and hardy shrubs. 



Between March 13th and April 8th (1889) rain actually fell 

 three times in my vicinity ; twice the fall was insignificant, last- 

 ing only two or three minutes, but on March 19th rain fell 

 abundantly in Wadi Feirdn, from 7.15 a.m. to 9.30 a.m. Heavy 

 mists had obscured the peaks bordering this extensive valley 

 nearly all the preceding day ; the temperature during this rain- 

 fall was 52°, elevation about 1,900 feet. 



That heavy falls of rain and even of snow occur in December 

 and January in the Sinai region, is reported by many travellers ; 

 in the defile of Nakb-el-Hawi (5,000 feet), crossed by pilgrims en 

 route for the sacred mountain, the winter rains make veritable 

 torrents ; in 1867 the water rose to such a height in the valley 

 adjoining, Wadi-Selaf, as to wash away a camp of Bedouins, 

 causing a loss of 40 lives and of numerous cattle (Baedeker). 

 Capt. Palmer describes also a sudden precipitation so copious as 

 to fill the bottom of Wadi Feiidn to the depth of several feet, 

 causing the party to seek high ground. That the Oasis of 

 Feirdn was once the site of a village of anchorites and monks 

 sufficiently important to become an Episcopal See, is known to 

 students of history; this was in the second to the sixth century 

 A.D. A few cut stones, the capital of one column, and ruined 

 sites, alone remain to indicate the locality. 



Judging by the great boulders and trunks of palms which I 

 saw in the lower part of this valley, I am disposed to believe 

 that heavy rains are more frequent than supposed. Casual and 

 irregular observations of rainfall by travellers, who of neces- 

 sity move their tents almost daily, and who choose favorable 

 seasons for the journey, are of course unreliable data for scien- 

 tific conclusions as to the meteorology of the country. Unfor- 

 tunately, the monks residing at the Monastery of St. Catherine, 

 and who enjoy great opportunities, care for none of these things. 



Eeturning for a moment in tliought to the Nile valley, I note 

 that although the sun usually shines with great brilliancy, it 

 is a mistake to infer that the sky is uniformly cloudless. In 

 March tiiere were many cloudy days, some of which would, in 

 this country, have been regarded as rain-precursors. 



Witids. — Powerful winds sweep across the plains and through 

 the valleys of Arabia Petraea, with a violence and continuity 

 that I have not elsewhere experienced. In tiie spring months 

 the prevailing wind in the desert is from the north and north- 

 west, down the Gulf. This wind is a cool one, but it occasion- 

 ally 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 traveller's skin 



