43- 



NA TURE 



[June io, 1909 



THE WATER SUPPLY OF KENT. 



THE question of water supply, a matter of such 

 vital importance to corporate life, has been 

 studied from the practical and theoretical standpoint 

 by numerous authorities, but no hard-and-fast rules 

 can be laid down, owing to the fact that general 

 principles are subservient to local conditions. This 

 is, perhaps, the reason why the leading authorities 

 are so often contradictory. 



Owing, partly, to the large area of its outcrop and 

 subterranean extension beneath the Tertiary beds 

 of the northern part of the county, partly to its 

 great thickness, and partly to its unlimited capacity 

 for water storage, the Chalk is the most important 

 member of the Cretaceous series which is so finely 

 developed in Kent, and yet it is rare to find two 

 authorities agreeing on any point with regard to the 

 behaviour of water in Chalk, while all speak from 

 many years of experience. 



The reason is that the question is far more com- 

 plex than appears at first sight ; as Whitaker points 

 out, the absorbent capacity is modified by the extent 

 of exposure, which is not always made clear by 

 geological maps. The surface mav be bare, in which 

 case the absorptive power is very high, in some 

 cases, where the Chalk is open and fissured, large 

 volumes of water being swallowed up with extra- 

 ordinary rapidity ; in others, where the soil is un- 

 usually thick or clayey, the absorption may be hin- 

 dered ; the case is modified by a covering of 

 permeable beds such as Drift gravels and sand, 

 and, again, where the Chalk is covered by beds of 

 varying character, and, finally, where the Chalk is 

 covered by beds of an impermeable character. Such 

 an area as the latter is, of course, to be definitely 

 excluded in calculating the absorptive area of the 

 Chalk. In Kent this tract is confined to those dis- 

 tricts where the London Clay covers the Chalk. 



Again, the storing and transmitting capacity of 

 the Chalk depends upon the physical nature of the 

 different beds, and as in Kent the Chalk attains 

 in many places a thickness of nearly 800 feet, it is 

 obviously natural to find the different zones differing 

 in character to a considerable extent ; and yet en- 

 gineering geologists have persistently ignored the 

 value of a knowledge of the palaeontological zones 

 of the Chalk, of which eight are represented in 

 Kent. There is no excuse for this apathy, since the 

 work of Dr. Rowe has placed the geology of the 

 Chalk upon a scientific footing. It is a striking 

 fact that in all the literature quoted in the extensive 

 bibliography, the author has only been able to find 

 a single work dealing with the zones of Chalk from 

 the point of view of the engineer. 



In this memoir, one of the most useful that the 

 Geological Survey has published, Mr. Whitaker dis- 

 cusses briefly the geological formations of Kent, and 

 the nature and causes of the different kinds of 

 springs occurring in the different beds, while a special 

 chapter is devoted to swallow-holes and nailbournes, 

 phenomena essentially characteristic of a Chalk area. 

 A valuable chapter on the rainfall of Kent, illus- 

 trated by a map, is contributed by Dr. H. R. Mill. 



The amount of water taken from springs in Kent 

 is very small ; there are only two large supplies, those 

 for Maidstone and Folkestone, and neither of these 

 is dependent upon the springs. 



The Chalk area of Kent is pierced by very 

 numerous wells for private or restricted use, but they 

 are being rapidly superseded by the institution of 



1 " The Water Supply of Kent : with Records of Sinkine<: and Bnrines." 

 By William Whitaker, F.R.S. With Contributions by Dr. H. Franklin 

 Parsons, Dr. H. R, Mill, and Dr. J, C. Thresh. (Memoirs of the Geoloaical 

 Survey of EngLind and Wales, 1908.) Pp, v + jog, (London : Published 

 for H,M. Stationen- Office by Wyman and Sons, Ltd., igo8,) Price is. 6ci. 



NO. 2067, VOL. 80] 



larger corporate water works, which are onlv wells 

 on a large scale. The quantity of water taken from 

 surface deposits, as at Tunbridge Wells, from the 

 Eocene beds, Lower Greensands, and sandy members 

 of the Hastings beds, is insignificant compared with 

 the amount provided by the Chalk, which supplies 

 all the larger towns, as .Ashford, Tonbridge, Dover, 

 and the Kentish part of London. 



Not the least interesting part of the book is the 

 147 pages occupied by sections of wells, and details 

 of a large number of borings are also included. 



Prominence is given to sections of some of the 

 shafts and Ixirings put down with the view of proving 

 and working coal; these pages summarise our know- 

 ledge of the subterranean geology of Kent as it 

 stood two years ago, but the impetus recently given 

 by the new exploring companies since the discovery 

 of the splendid coal-seams at the borings of Walder- 

 share and Fredville has doubled the information avail- 

 able, though it has not yet all been made public. 

 It is unfortunate that the author contented himself 

 with the meagre sections of these two famous bore- 

 holes given by Boyd Dawkins in his evidence before 

 the Royal Commission on Coal Supplies ; if he had 

 applied direct to the companies, the information 

 would surely have been willingly given. 



The work is completed by a large number of 

 analyses of both well and spring waters, and a 

 number of notes on various subjects, some of con- 

 siderable interest, such as the effect of heavy pump- 

 ing, infiltration of salt water, and the deep borings 

 at Cliffe and Frindsbury, but the vital question of 

 pollution might have received more attention. 



As a striking instance of the value of well-managed 

 public water companies over purely local . sources we 

 may quote the following remarks from the report of an 

 analysis of a sample of wate;- from Delf stream, which 

 gave drinking water to Sandwich until recently : — 



"Colour objectionable, a dirty pale yellow; micro- 

 scopic examination eminently unsatisfactor)'. The 

 residue .... was full of animal matter; ... it 

 would be much more appropriate to call the liquid 

 from this pump sewage rather than water .... 

 however valuable this fluid might be as a liquid, 

 manure, and it would be impossible to deny that it 

 has a certain value in this respect, it should not be 

 used as water." • M. B. 



THE WINNIPEG MEETING OF THE BRITISH 



ASSOCIATION. 

 'T~*HE British .Association Will hold its annual 

 ^ meeting in Winnipeg from August 25 to Sep- 

 tember I, under the presidency of Sir I. J. Thomson, 

 F.R.S. 



Regular attendants at meetings of the .Association 

 have become accustomed to reminiscences of previous 

 meetings in the same city. Thus, when tlie asso- 

 ciation meets in Great Britain, the expression " When 

 we met here twenty-five years ago," or "At our 

 meeting fifty years ago," has become a stereotyped 

 part of the presidential addresses. A meeting of the 

 association in Winnipeg thirty years, or even twenty- 

 five years, ago would have been almost an impossi- 

 bility. At that period ^^^innipeg was little more than 

 a Hudson's Bay Company's trading post — Upper Fort 

 Garry^ — the population of the scattered settlement 

 numbering only some 2000 people, mostly farmers. 

 Winnipeg could not have been reached by the Cana- 

 dian Pacific main line until some six years later; 

 passengers arrived by stern-wheel steamers of the 

 Mississippi type from Moorhead, Minnesota, via the 

 Red River; or came by irregular trains over the Great 

 Northern Railway from St. Paul to St. Boniface 



