Page:Transactions of the Provincial Medical and Surgical Association, volume 2.djvu/196

 rock, along the southern bank of the river, hang the beautiful Leigh Woods. Below Prince's Buildings and the York Crescent, which stand upon the mountain limestone or superjacent limestone shale, we find the millstone grit, which may also be seen on the other side of the river, reposing upon the limestone. All the lower part of Clifton, including the Hotwell Road, and some very high ground, for instance, that of the Paragon and Windsor Terrace, are built upon this rock. Proceeding in a north-easterly direction, we find it over Brandon Hill, Tyndal Park, the upper part of Park-street, and at the foot of St. Michael's Hill, where it disappears under the superincumbent red sandstone and lias. It is not easy to determine, precisely, the boundaries of the millstone grit, as the ground below the parts just enumerated is thickly covered with buildings, and no other outcroppings are visible than at the places just mentioned. As the distance between the known course of these strata and those of the red sandstone is by no means great, the determination of the boundaries is not of much importance. The remainder of Bristol, that is, about three-fourths, is situated on the red ground; from this, however, we must except a small portion north of St. Michael's Hill, which belongs to the lias.

The general character of mountain limestone is too well known to require description here. Elevated to a considerable height, inclined in its stratification, and covered with a shallow soil, it presents obvious advantages with respect to perflation of buildings, and non-detention of moisture on the surface; but, on the other hand, the hardness of its texture is a