From this digression we return to our third division of the Oolite proper, the _Lower Oolite_, as developed in Somersetshire (around Bath), and in Wiltshire (Tisbury, Braford, &c.), which has its own points of interest and of use. Here occurs the fuller’s earth, mostly found at a village near Bath, called Old Down, which possesses the peculiar property of absorbing the grease or oil remaining in cloth, and thus _fulling_ or thickening it. Here also is found that peculiar rubbly limestone, called “_Cornbrash_,”[92] in Wiltshire, which, on exposure to atmospheric agencies, soon decomposes, and by mixture with he ordinary constituents of the soil, makes an admirable material in agricultural operations. Here also we have the Bath Oolite, the quarries of which are very extensive, abundant in fossils, and the character of whose stone gives to the city of Bath that clean and aristocratic appearance which is so striking to the stranger approaching Bath from the Great Western Railway. “In this lower division,” says Lieutenant-Colonel Portlock, “also occurs the Bath oolite, which is an excellent stone for the delicate mouldings of gothic architecture, and is represented in France by the Caen stone, which was imported for the purpose by our early architects, as may be seen in the beautiful Temple Church.”[93] Of two varieties of Oolite, called “Barnack rag” and “Ketton stone,” obtained from the quarries in Rutlandshire and Northamptonshire, almost all the churches in Cambridgeshire, of the twelfth and thirteenth centuries, are built. As an instance, and illustrative of previous remarks, we may specify King’s College Chapel, Cambridge. Whoever has been to the top of that gem of gothic architecture, and walked outside where the stone is weathered, and has been supplemented in various indifferent ways, may there see the ripple marks of the old tides and winds, marking the ebb and flow of pre-Adamite phenomena; and little shells, some of them most tiny ones, but in beautiful preservation, once left in the soft calcareous sand, now embedded in the hard building stone. And here, before we speak of the fossils of the Oolite, we should like to be thoroughly understood about this same ripple-mark, of which we have more than once spoken, and which it seems desirable to explain. “Another structure, often conspicuous in fine-grained sandstones, is that commonly called “ripple-mark.” Either in quarries or natural cliffs, wherever the upper surface of a bed is exposed, it is often found to be not smooth or flat, but waved in small undulations, exactly like those so often seen on a sandy shore. Now, a good deal of misconstruction has, I think, arisen as to the origin of these small undulations or ripples in the sand, leading sometimes to a possibility of grave error in geological reasoning. People standing on the beach, and observing the gentle rippling motion of the waves, and a very similar form in the sand beneath them, have not