noon
Bleak plains -- through whose barren soil outcrops of blackened scoriæ , or sharp edges of black and brittle hornblende , appeared at every turn -- were interspersed with wadies , bounded by ridges of basalt and green-stone , rising from one hundred to two hundred feet high , and covered with a scanty vegetation of thorny acacias and clumps of camel-grass . Here and there a rolling hill was cut by a deep gorge , showing where , after rain , a mighty torrent must foam its way ; and , more rarely still , a stagnant pool of saltish or brackish water was marked out by a cluster of daum palms . On all sides jackals howled dismally during the night ; and above , during the day , an occasional vulture wheeled , fresh from the carcass of some poor mule dead by the wayside . Such was the appearance of the land through which the caravan wound its way , beneath a sky peculiar to Arabia -- purple at night , white and terrible in its heat at noon , yet ever strange , weird and impressive . But one incident worth recounting occurred on the way . Yusuf , Amzi , and the boy Dumah had been traveling side by side for some time . The way , at that particular spot , led over a plain which afforded comparatively easy traveling , and thus gave a better opportunity for conversation .