Permian Strata.
Durham.—Large quantities of water are pumped from the lower Permian sandstone beneath the magnesian limestone of this county, and are used for the supply of the towns of Sunderland, South Shields, Jarrow, and many villages. The quantity, calculated by Daglish and Foster to reach five millions of gallons a day, is obtained from an area of fifty square miles overlying the coal measures. The water-level has not been lowered in the rock by these operations. Along the coast it is that of mean tide, and inland rises to a level of 180 feet. In the coal measures below there is little water, and that little is saline. Sedgwick gives the strata as red gypseous marls, 100 feet; thin bedded grey limestone, 80 feet; red gypseous marls, slightly salt, 200 feet; magnesian limestone, 500 feet; marl slate, 60 feet; lower red sandstone, 200 feet.
Coventry.—Warwickshire. The town is supplied with 750,000 gallons of water a day from two bore-holes made in the bottom of the reservoir. The bore-holes are respectively 6 inches and 8 inches diameter, and 200 feet and 300 feet deep. The town is situated on the Permian formation, but Latham states that the supply is procured from the red sandstone, and, from observations made, it has been found that the two bore-holes yield water at the rate of 700 gallons a minute.