Meanwhile, it is not only men and women whom we miss--men laboring by the river side; women with babies astride on their shoulders, or water-jars balanced on their heads--but birds, beasts, boats; everything that we have been used to see along the river. The buffaloes dozing at midday in the shallows, the camels stalking home in single file toward sunset, the water-fowl haunting the sand-banks, seem suddenly to have vanished. Even donkeys are now rare; and as for horses, I do not remember to have seen one during the seven weeks we spent in Nubia. All night, too, instead of the usual chorus of dogs barking furiously from village to village, we hear only the long-drawn wail of an occasional jackal. It is not wonderful, however, that animal life should be scarce in a district where the scant soil yields barely food enough for those who till it. To realize how very scant it is, one needs only to remember that about Derr, where it is at its widest, the annual deposit nowhere exceeds half a mile in breadth; while for the most part of the way between Philæ and Wady Halfeh--a distance of two hundred and ten miles--it averages from six to sixty yards. Here, then, more than ever, one seems to see how entirely these lands which we call Egypt and Nubia are nothing but the banks of one solitary river in the midst of a world of desert. In Egypt, the valley is often so wide that one forgets the stony waste beyond the corn-lands. But in Nubia the desert is ever present. We cannot forget it, if we would. The barren mountains press upon our path, showering down avalanches of granite on the one side and torrents of yellow sand on the other. We know that those stones are always falling; that those sands are always drifting; that the river has hard work to hold its own; and that the desert is silently encroaching day by day. These golden sand-streams are the newest and most beautiful features in the landscape. They pour down from the high level of the Libyan desert just as the snows of Switzerland pour down from the upper plateaux of the Alps. Through every ravine and gap they find a channel--here trickling in tiny rivulets; flowing yonder in broad torrents that widen to the river.