Holmesdale Natural History Club. 19 



At Kedhill the lower greensand attains a thickness of from 400 to 500 feet. 

 It possesses good filtering powers, purifying the water from organic con- 

 taminations, and is in this respect important as a source of water supply. 

 For this purpose the formation in the eastern part of Surrey, from Dorking 

 to Limpsfield, was considered by Mr. Gilford to be best adapted, the broader 

 portion further west not being so readily available owing to faults, and to 

 the protruding of the Wealden beds. He then alluded to the Caterham 

 waterworks, which he considered to be probably too near the chalk escarp- 

 ment, as the supply in the autumn is at times deficient. He recommended 

 that the Reigate Waterworks Company should abandon their surface supply, 

 and bore through the gault (which would eflEeclually prevent surface 

 contamination) into the lower greensand, whence a practically unlimited 

 supply might be obtained. 



In the discussion which followed, Dr. Bossey advocated deep wells 

 further north than the line of outcrop of the gault, similar to that of the 

 Caterham Company, thus tapping the water-bearing strata at their lowest 

 level, where the most abundant sujjply will be found. 



Evening Meeting, AiMl ISth, 1879. Mr. E. C. Baxter read a paper 

 entitled " A Short Description of the Sub-Weaklen Gypsiim Company's 

 Works," as follows : — 



I had originally intended to describe the worlss at Mountfield only, but 

 I have since thought that it would make the paper more interesting if 1 gave 

 a section of the shaft, with some few brief remarks on the strata, and a 

 short account of the boring. 



The boring was commenced in August, 1872, by a society of gentlemen, 

 with Professor A. C. Ramsay as chairman, and was carried to a depth of 

 1018 feet, when an accident happened to the rods, and it was found im- 

 possible to continue the work. A new boring was commenced in February, 

 1875, and continued to a depth of 1,905 feet, when another accident 

 occurring, the work was abandoned. The cost of the two borings was over 

 £6,000. The object of the boring was to ascertain the nature and thickness 

 of the strata beneath the lowest series of tlie Wealden formation, and also 

 to discover whether the carboniferous strata of Belgium and the Boulonnaia 

 district of France extended across the Channel in this direction. The great 

 thickness of the Kimmeridgc clay p)revented this latter question being solved. 

 On looking to the section j'ou will notice some 20 feet of yellow clay, 

 followed by bands of calcareous shales and impure limestone, which extend 

 to adepth of some 125 feet. From this to a depth of 165 feet we have beds 

 of gypsum and gypseous shales and limestone. Below these beds we have 

 beds of sandstone of different qualities, extending to a depth of some 255 

 feet, below which I do not intend describing. The gypsum is contained 

 between regular beds of shales and limestones, which are themselves also 

 veined with thin layers of gypsum. The body of the gj'psum, however, has 

 no stratification, but :st',\istcd and contorted in every conceivable waj-, 

 and varies in quantity and colour every few yards. The bulk is of a dark 



