Should the fastenings of the horse, instead of being woollen, be of iron, the operation is more difficult. The preliminary arrangements are the same, but, once fairly at work, the _hammaze_ cautiously raises the clog up to the knee, and binds it there with his camel's rope, which he throws round the animal's neck, and leads it out very slowly. As soon as he has rejoined his comrades and is sufficiently far from the scene of his exploits, he bethinks him of giving his prize the liberty that is still wanting. He therefore removes the clog by means of a small saw, or picklock; at the worst he turns the padlock to the outside of the animal's legs and shatters it with a pistol ball, or else fills it with powder and blows it open. The explosion, however, rouses the owners of the animal, who set out in search of it, but nearly always in vain. The night is dark, and the robbers separate; though, if things come to the worst, they abandon their prize to save their lives. Sometime the master of a tent is troubled by the barking of the dogs, and awakens his people by calling out to them, _El hayi rah hena_, "there is somebody here." They go out, and, finding nothing, they conclude that a hyæna, or a jackal, has occasioned the uproar, and so turn in again. The thieves then come out of their hiding-places, and perhaps proceed to some other _douar_ that is less upon the watch. In preparing for a _khriana_, each one provides himself with a pistol which he secretes under his burnous, a knife, a thick cudgel with a cord at one end, and a poniard. If a robber fancies that the dogs will distinguish him because of the whiteness of his garments, he leaves them with his comrades, and enters the _douar_ entirely naked, his knife in one hand and the cudgel in the other. It is a popular belief in the Sahara that a man in a complete state of nudity is invisible in a dark night. A vicious horse, or one that is thoroughbred, or entire, is safe from robbers. Their habit of neighing on seeing a man would betray the plunderers. To avoid being scented by the dogs the precaution is taken to stalk up the wind. There are likewise other details which should not be neglected—the absence of moonlight, for instance. The twenty-first of the Mussulman month is the right time for setting out, and the night of the twenty-second is usually the most favourable for the execution of the enterprise. Dust and a high wind are useful allies, but rain is treacherous, for, by moistening the soil so as to retain foot-marks, it favours the pursuit. The cold season is the best for robberies of this character. There is a common saying: "In winter, cattle-stealing, because the dog sleeps in the tent. In summer, theft in the tent, because the dog goes away to sleep."