GEOLOGY Limestone gradually rises as the formation is followed eastward, and a permanent water-supply is found at a less and less depth from the sur- face. Finally after it has passed beneath the main outcrops of the Great Oolite Series it becomes saturated with water throughout nearly its whole thickness, and when a boring is put down through the overlying beds the water rises as an artesian spring. It should be mentioned however that some of the Limestone beds appear to be more permeable than others, so that they or the planes between such beds act as conduits for the water which is passing eastward. These horizons are the ' springs ' of the well sinkers and boring contractors, and it often happens that several such water-bearing conduits are traversed in the progress of a boring, the water from each rising some way up the bore-hole until at length one is met with that yields a strong and sufficient supply. 15
