G. Boicker — Water-supply of East Kent. 209 



tbe water is not good, and secondly, because there is no high land 

 of this formation to receive the rainfall, nor is it certain that it 

 would be met with in any thickness east of Dover.^ 



The slight anticlinal ridge of the Thanet Chalk has yielded water 

 for the present supply of Ramsgate, Margate, and Broadstairs ; but 

 in dry seasons the supply has not equalled the demand, and supple- 

 mentary wells have been sunk ; these, however, all derive their supply 

 from the exceedingly porous beds of the Upper Chalk, the wells not 

 reaching much below the sea-level, about which point the line of 

 saturation of the Chalk is there reached. From the fact that one of 

 these, the Southwood Waterworks near Ramsgate, became bi'ackish 

 from the influx of sea-water, the engineers of these waterworks 

 appear to have been afraid to sink deeper in the Chalk. It is pro- 

 verbially foolish to prophesy unless you know ; but I would 

 venture to suggest that the future water-supply of Thanet must be 

 sought for in a well reaching down nearly to the Gault. For though 

 there is every appearance that the whole depth of the Chalk strata of 

 Kent are to be found here (the Thanet beds reposing on the higher 

 beds at Margate, St. Peter's, and Broadstairs), yet there should be 

 no difficulty in piercing the Chalk, and I should expect an unlimited 

 supply of good water would be found in the Lower Chalk. Should, 

 such be the case, there would be no danger of its being contaminated 

 with sea-water, if a site were chosen not too near the sea, or 

 directly in a line of fault. If the sti"atum pierced was in a state of 

 saturation, there would be no reason to fear that sea-water would 

 replace the fresh. 



One great advantage of the water derived from deep Chalk strata 

 is its great purity, the only drawback being its exceeding hardness, 

 from the presence of bicarbonate of lime ; this may, however, be got 

 rid of by adopting the admirable method employed at Canterbury, of 

 passing lime water in certain proportions into the fresh pumped 

 water, which, uniting with the excess of acid in the bicarbonate of lime 

 in solution, precipitates it as an impalpable powder, and at the same 

 time killing all organic impurities and precipitating them with the lime. 



It now only remains for me to explain the supplementary section 

 and well notes which have been placed at my disposal. Mr. Bland's 

 paper, already alluded to, is entitled, "Measui'ements of the Altitudes 

 of the Hills and Valleys and the Depths of Wells through a Part of 

 Kent, undertaken for the purpose of ascertaining the Height of the 

 Springs above the Sea-level," and referring chiefly to the Chalk in and 

 around Sittingbourne in the years 1827 and 1828, with the rainfall 

 and state of the weather from 1819 to 1829. Privately printed at 

 Sittingbourne. For the loan of this interesting paper I am indebted 

 to the Rev. C. J. Wimberley, Sibertswold Vicarage. 



Notes on the Petham Nailbourne from 1772 to 1869. Communi- 

 cated by Mr. James Reid, of Canterbury. " The Nailbourne came 

 into Shamford Street, Feb. 22, 1772, and continued to run through 

 the street till June 16, 1772. It came into the street again, March 

 7, 1774, and continued running till June 28, 1774. It came into 



1 See section in Mr. Whitaker's paper, Quart. Journ. Geol. Soc. vol. xlii. p. 36. 



DECADE ni. VOL. IV. KG. V. 14 



