404 



REPORT — 1878. 



■012 part in 100,000, or # 008 grain per gallon, in Garner's spring, North- 

 ampton. In fact, " unpolluted spring water from the Oolites is unsur- 

 passed in its comparative freedom from all kinds of organic impurity." 



The oolitic rocks are very porons, absorbing and holding enormous 

 volumes of water, which are again delivered as springs usually of great 

 size. As water-bearing rocks are equal, if not superior, for the purifica- 

 tion and storage of water, the oolitic rocks are equal, if not superior, to 

 the chalk itself. But this vast store of magnificent water is rarely used 

 by communities until it is hopelessly polluted. The analyses show that 

 great care should be exercised to cut off surface contamination in deep 

 wells, and that shallow wells are absolutely unsafe. 



An area of no less than 6671 square miles is occupied by the oolitic 

 rocks of England, with an annual average absorption of not less than 

 10 in. of rainfall, a figure probably much below the real average. 



Professor Hull describes the two chief sources of springs among the 

 Cotteswolds, at the base of the Great Oolite, or Stonefield slate, at its 

 junction with the Fuller's Earth, and at the junction of the Upper Lias 

 clay with the overlying sands. To the latter horizon belong the seven 

 springs forming the source of the Thames. Smaller springs issue in the 

 district at the base of the Lias marlstones and the upper surfaces of 

 forest marble clays. 



Gloucester is partially supplied by springs in the flanks of Robin's 

 Wood Hill, thrown out by the Lias, which, with the surface drainage of 

 1,500 acres, are collected in a reservoir holding 62,000,000 gallons. The 

 water is nineteen and a half degrees of hardness, which could be reduced 

 to three and a hah by Clark's process. 



Three springs at Cheltenham are collected along the flanks of the hills 

 in bricked wells, and conveyed to the reservoirs at Hewlett's Hill and 

 Leckhampton, together holding 35,000,000 gallons. Above 300,000 

 gallons are daily delivered. The water is much softer than most oolitic 

 springs, the hardness being only 15 - 0, of which 6 - is permanent ; that of 

 Haydon, near Cheltenham, is no less than 45' 7, of which 13 - 4 is per- 

 manent. 



The saline springs of Cheltenham rise, according to Professor Hull, 

 like the water in artesian borings, along planes or fissures in the Lower 

 Lias, and are probably from water percolating through salt-bearing Keuper, 

 which outcrops at high elevations, as first explained by Sir Roderick 

 Murchison. 



