DATES OF EGYPT AND THE SUDAN. 13 
p. 8), where that variety is at its best, though probably the air at 
Dakhleh is much drier. 
This comparison throws light on the heat requirements of the off- 
shoots of the Saidy, which we are now importing, and suggests that 
the Coachella and Imperial Valleys of California will probably prove 
best adapted to its culture. As seen by the writer at Khargeh and 
Dakhleh, and after arrival at Fayum by camel from Baharieh, these 
dates are packed in solid masses in flattened baskets of braided date- 
leaf pinne, holding 80 or 160 rotls each; that is, either four or two 
of them make an ardeb weight of about 320 pounds, the usual camel 
load. At Dakhleh the usual price is about 50 piasters, or $2.50, for 
an ardeb, but in years of crop shortage the price advances sometimes 
to 70 piasters, or about $3.50 per ardeb, even this being but a frac- 
tion over a cent a pound. The best information available shows that 
they bring wholesale about 34 cents a pound in the valley and retail 
in the stalls at 1 piaster per rotl, or about 5 cents a pound. 
The Corporation of Western Egypt, an English syndicate which 
formerly operated a series of trading stores in Dakhleh, tried the 
experiment of packing these dates in attractive cartons for the Eng- 
lish market, but, while they found a ready sale, the extra cost of camel 
transportation to the railroad necessitated by the improved pack, 
left very little margin for profit. With rail and steamer transporta- 
tion at the door, so to speak, in Nile Valley towns, this excellent oasis 
variety ought to be a very profitable one to plant in the portions of 
Upper Egypt having temperatures most nearly corresponding with 
the oases, probably Girgeh and Keneh Provinces, which are now 
taxed on 1,250,000 unprofitable balady trees. 3 
THE DESERT TROPICAL ZONE. 
The desert tropical zone is marked by a decided increase in tem- 
perature over the lower portion of the Nile Valley and a lowering of 
the relative humidity to below even that of Dakhleh, in the heart of 
the Libyan Desert. Perhaps, owing to local conditions at the observ- 
ing station, the weather records for Aswan (lat. N. 24° 2’ 25’’) show 
higher monthly means for July, August, and September than Wadi 
Halfa (fig. 2), just within the Tropics (lat. 21° 54’ 49’’). These 
temperatures would doubtless be too high for the upper portion of 
the desert subtropical zone from Luxor to Aswan, where the date 
culture of this zone practically ends, on account of the submergence 
of the narrow valley lands by the Aswan reservoir. 
There is a decided step in temperature conditions between this 
region and the northern portion of the desert tropical zone repre- 
sented by Ibrim. Scattered groves of dates appear shortly south of 
the Tropic of Cancer, but the heaviest culture begins about Korosko 
