[28] It is a very wide valley, nay an extensive plain. But the Doctor writes about it before he arrives there.
[29] Tholh—الظلح—Acacia gummifera, (Willd.) It bears what the Moors and Arabs call Smug Elârab (صمغ العرب), or "Gum Arabic." This is the most hardy tree of The Desert, and, like the karub-trees of Malta, strikes its roots into the very stones.
[30] Dr. Oudney says, who was a man of science:—"Rain sometimes falls in the valley (of Sherkee, Fezzan,) sufficient to overflow the surface and form mountain torrents. But it has no regular periods, five, eight, and nine years frequently intervening between each time. Thus, no trust can be placed in the occurrence of rain, and no application made in agricultural concerns." In truth, the rain which falls in these uncertain intervals, seems to answer no available purpose, unless to feed the wells and under-currents of water.
[31] The blowing hot and cold with the same breath is here a reality, or thereabouts.
[32] Adapted from an anonymous piece, called "The Dying Negro."
[33] "But we will cause thee to turn towards a Kiblah that will please thee. Turn, therefore, thy face towards the holy temple of Mecca; and wherever ye be, turn your faces towards that place."—Surat ii.
