234 PRODUCTS.

form eight miles in two hours. In the cool of the morning or evening, and when cheered up by the songs of the drivers, these animals become more lively, and increase their paces to one third of their speed. Their organs of sight and smell are very acute, for they scent the vicinity of water at a distance of half a day's journey or further, and make it known by snuffing with the upper lip, in sign of pleasure. By night they perform the office of a watchful dog ; for if a man, or an animal approach the caravan, or a wild beast give tongue even at a great distance, the camels instantly perceive it, prick their ears, and stretch their long necks towards the suspected quarter, to draw the attention of their keepers to the interruption. Of no less utility is the dromedary, a camel of more slender build, and broken in for riding. It was formerly an erroneous hypothesis that the dromedary was a different animal from the camel, and the former was generally depicted with two humps ; but this is a fallacy, for the dromedary is nothing but a camel, and the variation in the name is merely made use of by the inhabitants of the East to indicate that it is broken-in for riding, and not for carrying loads. They select from among the young camels such as are most slightly* built, and most light of foot, never lay any load upon their backs except the saddle, and thus gradually break them in for this important service. No horse can keep up with the dromedary, when proceeding at full trot. When this animal is at the top of its speed, the rider is obliged to bind a hand-