Of the Jewish system of encampment the Mosaic books have left a detailed description. From the period of the sojourn in the wilderness to the crossing of the Jordan the twelve tribes were formed into four great armies, encamping in as many fronts, or forming a square, with a great space in the rear, where the tabernacle of the Lord was placed, surrounded by the tribe of Levi and the bodies of carriers, etc. by the stalls of the cattle and the baggage: the four fronts faced the cardinal points while the march was eastward, but as Judah continued to lead the van, it follows that when the Jordan was to be crossed the direction became westward, and therefore the general arrangement, so far as the cardinal points were concerned, was reversed. It does not appear that, during this time, Israel ever had lines of defense thrown up; but in after ages, when only single armies came into the field, it is probable that the castral disposition was not invariably quadrangular; and, from the many positions indicated on the crests of steep mountains, the fronts were clearly adapted to the ground and to the space which it was necessary to occupy. The rear of such positions, or the square camps in the plain, appear from the marginal reading of; , to have been enclosed with a line of carts or chariots, which, from the remotest period, was a practice among all the nomad nations of the north. The book of Numbers is so explicit on the subject of encampment, and the march of the Israelites, that no particular explanation seems to be necessary.