Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/214

 rhomb, sometimes that of the dog's-tooth, and sometimes very complicated figures with numerous truncations. The whole cavity of the nodule is generally lined with small crystals, which are highly phosphorescent when thrown on an iron plate heated almost to redness.

On cutting through the loam there is generally found a bed of ochreous iron-stone about 1$$\scriptstyle \frac 12$$ foot thick. It is not known to what distance this bed of loam extends. The nodules have as yet been found chiefly in Hung-road wood, and some varying a little in appearance are seen on the opposite side of the river.

To the west of Crokeme Pill you find only a low alluvial plain, scarcely raised above high-water mark, and this continues on both sides of the Avon until it falls into the Severn.

With regard to the springs in the district I have been describing, it may be observed that those in the limestone are low and situated in the ravines, breaking out in many cases between high and low water mark. The hot spring at the Wells rises in the limestone 26 feet below high water mark, and 10 feet above low water, and no water is found at Clifton until the wells are sunk nearly to that depth. When you come to the sand-ridge upon which Leigh is situated, the springs are always found to rise in a high level, and they afford a good supply of water. In the horizontal strata to the west of Leigh very good water is obtained by sinking to the second or thick bed of breccia, or at the utmost by sinking a few feet into the stratum. There is a little spring in Hung-road wood which though perfectly clear has the property of covering every thing over which it flows with a brown calcareous crust. The quantity of water is small, and in summer the stream is frequently dried up.

As to the nature of the soil, the valley of Bristol and Ashton is as verdant an extent of pasture land as any in the kingdom. Its rich