Let us now pass on to consider the Fountain of the Virgin, the only useful spring in the neighbourhood of Jerusalem, of which I have already given an account[884], as well as of the upper pool of Siloam, which is supplied by the Fountain; but I have not yet described the phenomenon of its intermittence, the quality of its water, and the conduit connecting the two places. S. Jerome, as I have already observed, and the historians of the Crusades, noticed that the flow of the water was not regular, so that the occurrence is by no means novel. Dr Robinson[885] gives the following account of it: "As we were preparing to measure the basin of the upper fountain and explore the passage leading from it, my companion was standing on the lower step near the water, with one foot on the step and the other on a loose stone lying in the basin. All at once he perceived the water coming into his shoe; and supposing the stone had rolled, he withdrew his foot to the step; which however was also now covered with water. This instantly excited our curiosity; and we now perceived the water rapidly bubbling up from under the lower step. In less than five minutes it had risen in the basin nearly or quite a foot; and we could hear it gurgling off through the interior passage. In ten minutes more it had ceased to flow; and the water in the basin was again reduced to its former level." I have repeatedly observed the same thing, and for some time was unable to explain it, and therefore questioned the villagers of Siloam, and so learnt, from the more ignorant, the story of the dragon, and from the wiser, that the spring had a flux and reflux like the sea; and they were prepared to instruct me on its periodicity. How I at last discovered the true cause I will relate in speaking of the _Hammam es-Shefa_. Meanwhile I only mention, as an unquestionable fact, that the phenomenon undoubtedly occurs both in the rainy and dry seasons, but that the supply is greater in the former than in the latter.