ON THE CIRCULATION OF UNDERGROUND WATERS. 71 



supplied me with information respecting the Liverpool wells in the form 

 which 1 thought desirable for my purpose. 



I append his statement of the analyses of the water of Bootlc, Green-Lane, 

 Windsor, and Dudlow-Lane wells from 18G8 to 1876, together with very 

 valuable information kindly given me by Mr. Deacon, the borough engineer, 

 as to the nature of the wells and the level of the water in the wells on the 

 dates of the analyses. At my request he was also good enough to supple- 

 ment it by a table showing the average daily yield of the several wells from 

 1868 to 1876. 



To make the information more complete, Dr. Brown has also, for purpose 

 of comparison, recalculated the analyses of several Liverpool wells given in 

 Bobert Stephenson's Beport of 1S50 into the terms of his own analyses ; I 

 also append these. 



Having vainly endeavoured to discover some connexion between the rain- 

 fall and the yield of the wells by comparing Mr. Deacon's table with the 

 rainfall table supplied by Mr. Symons, which I also append, it suggested 

 itself to me that relative hardness might be a test of surface-percolation ; but 

 Dr. Brown states that " I do not find that there is any regular difference 

 between the hardness in summer and winter. Differences can be traced to 

 heavy rainfall and the rate of pumping." It is also clear, from a perusal of 

 what Dr. Brown says of the Bootle well, that heavy rainfall does affect its 

 hardness ; but that the effect is only a local one is clear from the resumption 

 of hardness which took place after 7 days' pumping. As local percolation 

 means greater danger of organic contamination, it is open to question whether 

 it should not be to a great extent prevented. 



A perusal of Dr. Brown's statements seems to show that the hardness has 

 increased from 15° in 1868 to 22°-28 in 1876 in the Bootle well ; in the 

 Green-Lane well from 13° in 186S to 18° in 1876 ; in the Windsor well from 

 15° in 1868 to 2U° in 1876 ; and in Dudlow-Lane well from 6|° in 1868 

 to 7^° in 1876. In some cases the deep-bore water is softer than the well- 

 water, in others harder. 



On comparing these analyses with those recalculated from Bobert Ste- 

 phenson's report by Dr. Brown and his remarks thereon, it is impossible not 

 to be struck with the fact that the Corporation wells at Bootle and Windsor 

 are now yielding water of almost identical quality with that supplied in 

 1850, although there have been many intermediate fluctuations. Taken 

 together with the steady increase of hardness since 1868, it seems to show 

 that the deepening and boring done since 1850 must have had the effect of 

 softening the water, but that now it is, through greater pumping strain, 

 returning to its original hardness ; in fact, the old conditions are reintro- 

 duced on a larger scale. 



It is consolatory as showing that the hardness is not due to the depth or 

 extent of the contributing area, but to the actual drain on the rocks. This 

 is a point that demands more consideration than I have yet been able to give 

 it, pressure of professional work having driven me to the last day almost for 

 preparing this Beport. I quite agree with Dr. Brown also that there is very 

 little, if any, percolation of sea-water into the Corporation w T ells, and con- 

 sider his arguments are conclusive on that point; there is no doubt, however, 

 that sea-water does enter wells in some cases. It is naturally what we 

 would expect ; but each case must be taken by its own evidences, and the 

 fact remains that though the mean level of the water in the Bootle well was 

 about 20 feet below low-water mark in 1876 and its distance from the sea 

 is under a mile, witli the dip of the rocks from the 6ea towards it, yet no 



