206 OOLITIC, OR JURASSIC LIMESTONES. the influence of the atmosphere; of which instances will be presently adduced. When first quarried it is often sufficiently soft to be cut with the saw ; but hardens on exposure. This is the case both at Bath and at Cheltenham. Geological Position of the best Building Stones. The Jurassic series contains four distinct formations of Oolitic limestone, some of which are divisible into distinct bands, with varying petrological characters. These, in ascending order, are (i) The Inferior Oolite; (2) The Great, or Bath, Oolite; (3) The Coralline Oolite, or Coral Rag; (4) The Portland lime stone. A short description of each of these will now be given. 1. Inferior Oolite. This formation is more fully developed in the Cotteswold Hills in Gloucestershire than in any other part of England, attaining at Leck- hampton Hill, near Cheltenham, a thickness of 264 ft., and furnishing two courses of a building stone which has probably been used in the construction of Gloucester Cathedral, the Abbey Church Tewkes bury, Sudeley Castle, and several of the ecclesiastical buildings which adorn the Yale of the Severn. From this spot as a centre, the freestones of the Inferior Oolite thin away towards the north, east, and south. The following is the section of the strata at Leckhampton Hill:— 1 1 E. Hull, ‘ Geol. of Cheltenham,’ Mem. Geol. Survey, 1857.