472 Geology of 



diminution could be anticipated with some degree of certainty. How- 

 ever, experience has shown that the height to which the water rises 

 has scarcely been affected in those localities where the wells are more 

 scattered, to about 3 to 4 inches only — except in particularly dry 

 seasons, whilst in those parts of the City where the wells are very 

 numerous and a great deal of water is required, the decrease in height 

 has been about four feet. Thus the artesian wells near the Museum 

 and in the Domain have lost only a few inches, whilst near the inter- 

 section of Cashel Street with High Street, the loss in height has been 

 estimated at four feet. The size of the pipes is usually \\ to 1^ 

 inches in diameter, those sunk by the City Authorities and some 

 private establishments are of larger size (2 inches). I do not know 

 how many artesian wells are in existence in Christchurch, but I 

 believe there are close upon a thousand, aud a similar number may 

 exist in the suburbs and adjoining districts. The result of several 

 analyses have shown that the water is remarkably pure. It is beauti- 

 fully clear, and having the mean temperature of Christchurch (about 

 53 deg.) all the year round, it is delightfully cool and refreshing in 

 summer. The analyses of Professor Bickerton, F.C.S., have shown 

 that its constituents vary in different localities, the total solids, 

 however, never exceeding 4 grains per gallon. 



There are two sources from which the water is derived, first from 

 leakage of the rivers, and secondly from rainfall on the plains. Whilst, 

 however, the heaviest freshets in the Waimakariri have never had the 

 least influence upon the water supply, the wells have been known to 

 rise four to five inches after heavy south-west rains, a continuance of 

 dry weather for several months lowering them just as much. It 

 appears, therefore, that the amount of water derived from leakage of 

 the rivers, is constant and not in any way influenced by their volume 

 at the time. In confirmation, the following observations made by 

 Dr. LI. Powell, F.L.S.. will be of interest, Dr. Powell placed a 

 gauge upon his artesian well in Worcester Street west in the early 

 part of 1875. During that year the water stood at an average of 25 

 inches in the glass tube. On November 28, after four days of heavy 

 south west rain, it reached 29 inches, its greatest height during that 

 year. The strongest North- westers with heavy floods in the Wai- 

 makariri did not however make the least alteration in the position of 

 the column of water. On October 27th, 1877, the level had fallen to 

 20f inches, whilst at the beginning of Nov. 1878 it only reached to 13 

 inches, during a time when fierce Nor' -westers had been raging 



