Personally, I liked these houses immensely; it was so easy to put nails in the walls solidly. As a rule, things I nail up fall down suddenly, without any warning, on some revered head--never on mine, because I take care not to place myself underneath the work of my own hands. In the Laghouat houses, however, you can plant a good long nail boldly. It enters as though into butter, you hang up your picture, or whatever it is, and then go outside and hang a pot of flowers or a water-pot on the point which has come through--and there you are, perfectly balanced on both sides! But these mud houses have one rather serious drawback. When it rains--fortunately this only occurs at very rare intervals--the buildings, unless strongly white washed, have a tendency to fall down and melt away into shapeless mud-heaps. This is all in the day’s work to the Arab, and does not upset him overmuch, unless a child--or what is to him worse, a sheep or horse--is buried in the ruins. He just camps out under a camel hair tent in the highest part of his garden, or, if he hasn’t a tent, under a carpet--everyone has a carpet. Then, when it ceases raining, he serenely rebuilds. “Tu cha Allah!” he says--“It is the will of God.” The rain-storms, though infrequent, are really terrifying when they do come. I have seen waves several feet high turning the corner of my house, and that half an hour after a downpour began. The river of sand, Oued M’zi, which becomes Oued Djdid farther on, fills with water in the twinkling of an eye, and is soon a deep, roaring torrent two miles broad; it is perfectly incredible the rapidity with which the floods rise. [Illustration: A LAGHOUT MUD-HOUSE--DURING THE RAIN-STORMS THESE BUILDINGS HAVE AN AWKWARD HABIT OF MELTING AWAY! _From a Photograph._] This Oued M’zi is supposed by the Roman historian Juba to be the real source of the Nile. It is an uncanny river, disappearing underground at various points for several days’ march. It finally disappears altogether at Cholt Melghir, but the Roman historian points out that after twenty days’ march it reappears as the source of the Nile. Some seven years before I arrived at Laghouat, I was informed, the M’zi rose to such a height that it bore all before it on the north side of the oasis. Men, women, children, tents, and herds were carried away for many kilometres, and the deaths by drowning numbered several hundred.