Seven Pillars of Wisdom by T.E. Lawrence

Having not a mouthful of water we of course ate nothing: which made it a continent night. Yet the certainty of drink on the morrow let us sleep easily, lying on our bellies to prevent the inflation of foodlessness. Arab habit was to fill themselves to vomiting point at each well, and either to go dry to the next; or, if they carried water, to use it lavishly at the first halt, drinking and bread-making. As my ambition was to avoid comment upon my difference, I copied them, trusting with reason that their physical superiority was not great enough to trap me into serious harm. Actually I only once went ill with thirst.

Next morning we rode down slopes, over a first ridge, and a second, and a third; each three miles from the other; till at eight o'clock we dismounted by the wells of Arfaja, the sweet-smelling bush so called being fragrant all about us. We found the Sirhan not a valley, but a long fault draining the country on each side of it and collecting the waters into the successive depressions of its bed. The ground surface was of flinty gravel, alternating with soft sand; and the aimless valleys seemed hardly able to trace their slow and involved levels between the loose sand-dunes, over which blew the feathery tamarisk; its whipcord roots binding the slopes together.