ON THB CIRCULATION OF UNDERGROUND WATERS. 365 



The water from the borehole contains 630 grains of solids and 

 39 grains of chlorine, and the yield is 400,000 gallons per day. 



Staffordshire. 



Mr. H. J. Marten, M.Inst. C.E., gives the following details of the bore- 

 hole sunk under his superintendence at Cosford, 9 miles from Wolver- 

 hampton, for the corporation waterworks of that town : — 



Ft. In. 



Upper mottled sandstone 461 6 



Pebble beds :— Ft. In. 



Upper pebble beds . . . . . . 165 6 



Argillaceous marl 85 



Lower pebble beds 128 



378 6 



Lower mottled sandstone ( + ) 789 



918 9 



He states the water rises to 9 feet above the level of the ground, or 

 about 201 feet above Ordnance datum, the natural discharge being at the 

 rate of 480,000 gallons a day. Opening a sluice 14 feet below this, the 

 natural discharge is 830,000 gallons a day. On pumping down the water 

 level 27 feet below the ' summit level,' the yield is increased to 

 1,320,000 gallons a day, and at 31 feet to 1,420,000 gallons per day of 12 

 hours. 



There was a slight briny ooze, estimated at about 300 gallons a day, 

 from the argillaceous marl bed. 



Mr. H. J. Marten also describes the Tamworth Waterworks well, sunk 

 at Hopwas, 2 miles west of that town : — 



Ft. In. 



Drift 16 6 



Ked marl, with rock bands 15 11 



Hard conglomerate 6 7 



Argillaceous marl 39 1 1 



Fissured sandstone 13 9 



Argillaceous marl 5 



Light fissured sandstone 30 4 



Red marl, with layers of greyish blue stone and balls of marl, 



with dark spot in centre, called ' fish-eyed ' marl . .410 



168 



No water was met with in the Hopwas well until the ' fish-eyed ' marl 

 was penetrated at 168 feet, when a large spring with an initial flow of 

 1,500,000 gallons a day was met with, and rose 39 feet in the well, or to 

 129 feet below the surface, which is about 306 feet above Ordnance, the 

 artesian level being 177 feet. A slight ooze took place in the fissured 

 sandstone, and a remarkable current of air was met with in it, fluctuating 

 with the barometrical changes, with a rising glass there being a decided 

 indraught from the well into the fissure, and the contrary taking place 

 with a falling barometer ; a very active outflow during the whole of one 

 day was succeeded at night by one of the most violent storms of the 

 period (1879). The fissure is evidently connected by passages with the 

 surface of the ground. 



