This second swallow is known as Swildon's Hole, Swildon being a corruption of Swithin. Years ago, in the course of a lawsuit, it was proved that the waters about the village of Priddy, which stands on the edge of this upland valley, find their way into the Axe, uniting their streams somewhere in the heart of the hill between this point and Wookey Hole. When there were storms on the hilltop, or the upland waters were fouled artificially, the Axe came out turbid. That the area drained by the underground Axe is a large one is proved by the size of the river, which must be formed by the junction of a good many streams of the volume of Eastwater and the Swildon brook. Probably that area extends as far east as Hillgrove, where a series of swallets in a woodland ravine are now being enlarged by Mr. Balch, with a view to an exploration of the underlying caverns. In 1901 Mr. Balch's party made a descent into Swildon's Hole, and got to a depth of 300 feet below the point of absorption, which is at the same level as the Eastwater Swallet and that at Hillgrove--that is, 780 feet above the sea. Difficulties having been put in the way of a more complete exploration by the owner of the field in which the swallet is situated, he turned his attention to the neighbouring stream of Eastwater, which, unfortunately, runs away through holes impenetrable to man, and therefore had not promised so easy a route into the unknown. Undeterred by the obvious difficulties, Mr. Balch set to work early in 1902, and, as he describes, made his way at last into the open passages underneath the swallet. In the course of two or three visits he reached a point nearly 500 feet below the cave mouth, and distant about 2000 feet in horizontal measurement. [Illustration: ENTRANCE TO GREAT CAVERN OF EASTWATER. _Photo by Bamforth, Holmfirth._] [Illustration: SECTION OF EASTWATER CAVERN.]