W. H. Hudleston — Recent Wells in Dorset. 217 



calculations as to supply refer to the second or main water. This 

 is considered to be sufficient in amount for all the requirements of 

 Wareham, but unfortunately it takes so long- to clear from fine sand 

 as to be detrimental to the pumps. , It is worthy of note that the 

 normal water-level in the Avell stands at a height of 91 feet from the 

 surface. Pumping may lower the water-level in the well to 97 feet 

 below the surface, but no amount of pumping can reduce the water- 

 level below this point. Hence Mr. Drew infers that there is a leakage 

 in the upper six feet of water, but that below this horizon there is no 

 lateral escape. In connection with this subject it may be useful to 

 remember that the whole of the 62 ft. 6 in. of the Second Sand-series 

 (C of the column) is saturated, and these saturated beds rest on the 

 second Clay or Pipeclay series of the Bagshots (D of the column) at 

 166 feet below the surface.^ The second water Avas first tapped in 

 a waterlogged sand at a depth of 108 feet from the surface, and there 

 is this anomaly in the situation, viz., that this water is much closer to 

 the Clay-series (B), which holds down the water, than it is to the 

 Clay-series (D), which holds it up. It may be that the proximitj^ of 

 a roof of clayey beds to the stratum from which the water is actually 

 drawn has a tendency to increase the amount of fine sediment which 

 hitherto has proved to be so prejudicial to this water. 



The Plateau-gravel {x). — -This is generally regarded as a Pleistocene 

 formation, but is certainly one of high antiquity, since it apparently 

 antedates the formation of both the valleys, viz., those of the Erome 

 and Pydel, which flank the block of Bagshots on which it rests.^ 

 It is of some importance economically, since the best road-metal of the 

 district is obtained from these beds. 



A very interesting and instructive section of these beds was 

 disclosed in January, 1905, during the excavation for the reservoir 

 on the summit of Worgret Hill. The excavation was more or less 

 a true square, and I selected the eastern side as a type of the whole 

 (see Fig. 3, based on a photograph taken by Mr. Churchill). The face 

 of gravel here is remarkably vertical, and the gravel holds together 

 so well as to cause surprise to some of the workmen. The peculiar 

 interest of the section at the reservoir arises from the discharged colour 

 noticeable in the upper part of the Plateau-gravel owing to the action 

 of peatj" acids having dissolved out or reduced the colouring matter, 

 chiefly iron and manganese oxides. This no doubt may be seen to 

 a certain extent in most gravel-pits ; but here a further feature has 

 been produced, viz., the irregular piping of the yellow unreduced 

 gravels by percolation from above. 



Particulars oj the Pagshot Beds. 



The Higher Sand-series {hi). — The general character of these beds 

 on the surface is that of the ordinary pale-yellow Bagshot Sands of 



1 The late Mr. L. W. Pike informed Mr. Drew that throughout the area of 

 Furzebrook and Grange, -n'here his operations for clay were carried on, he invariably 

 encountered at the same level a body of water which he believed to be identical with 

 that found in the well at Worgret. 



- See Proc. Dorset Field Club, vol. sxiii, pp. 149, 150, article " Creechbarrow." 



