At the end of the Valley of Siloam is another means of providing for the wants of the city in the matter of water; that is the well _Bir Eyub_, the ancient En-rogel, the boundary between the tribes of Judah and Benjamin[879]. It is situated in a deep narrow cleft of the valley, with precipitous mountains on every side; and formerly furnished water to Jerusalem, as it still continues to do, the inhabitants of Siloam driving a brisk trade during the summer droughts. I have already mentioned this well[880], and now proceed to give a more detailed account of it. In the month of October, 1858, _Bir Eyub_ was perfectly dry, and I availed myself of this event, unfortunate for Jerusalem, to descend into it. I reached the bottom, covered with fine sand, and there was able to examine a small cavity in the rock on the west, mentioned by Mejir ed-Din, from which the water flows in the rainy season. It was then completely dry, but I think that a spring formerly issued from it. I believe that the well (108 feet deep) is a cavity naturally worn by the constant flow of the water, but that it has afterwards been dressed with a chisel. It is now rectangular in plan, and gradually diminishes from the top to the bottom; the side walls are formed of large blocks in the lower part; as we ascend their size decreases; small holes occur among these at intervals, through which the rock can be seen, and the water runs into the well[881]. The stones recede, one behind the other, as we ascend, and they are perfectly united without any apparent trace of mortar, and must be bolted together with iron clamps or stone tenons to have enabled them to stand firm during so many centuries, and yet to seem likely to stand for many more. I have no doubt that the masonry is of the highest antiquity. The well is supplied by the rains which, sinking into the surrounding mountainous country, descend naturally to this vault at the lowest level. I have convinced myself of this by careful observation at the rainy seasons, and have ascertained that the well did not begin to fill until the rain had fallen for several days, and that the level of the water was not affected, unless the rain was heavy and continuous. I also found that the well did not overflow into the Kidron, unless this rain lasted for several days, and that it ceased when the fine weather returned, and a dry wind sprang up. In 1861 the rain was so heavy that the overflow lasted for fifteen days, but during this time there was very little sunshine in the neighbourhood of Jerusalem. The above explanation will, I trust, be satisfactory to all, except the Arabs, who account for the wonder in the following manner[882]: "We all know that the _Haram es-Sherîf_ is constantly guarded by sixty thousand angels. Now, by a decree of Heaven, while the heavenly host watch in prayer around the sacred rock (_es-Sakharah_), an equal number of evil spirits groan in the depths of the mountain,