Yol. 54.] PLOWTj^G well at NEWTON NOTTAGE. 303 



In this way I made nearly forty observations at intervals of one 

 hour (and in many cases at the intermediate half-hour) during 

 three successive days, covering the periods of several tidal waves. 

 The conditions during this time were very favourable. The tides 

 were slack and uniform ; the weather was calm and fine ; the 

 barometer did not vary J^ inch during the whole week ; and there 

 was no rain to introduce a source of error by filling up the land- 

 springs. 



Prom the results of these observations I constructed the curve 

 shown in the accompanying diagram (p. 304), in which the abscissae 

 represent the time-intervals elapsed since the period of low water, 

 and the ordinates show the depths of water in the well at the 

 corresponding times. In the upper part of the diagram I have 

 drawn a curve representing the height of the tide at the same 

 times (reduced to the same scale), assuming that the movement of 

 the tidal wave is regular and is expressed by a symmetrical curve, 

 as it would be on that coast in the absence of such disturbing causes 

 as wind. 



It will be evident, I think, from the diagram that the rise and 

 fall of the water-level in the well are as regular and symmetrical as 

 the rise and fall of the tide, but that the maximum depth, or the 

 crest of the wave, is 3 hours (-f- or — a few minutes only) behind 

 the crest of the tidal wave; and similarly that the minimum 

 depth, or the trough of the wave, in the well is 3 hours (approxi- 

 mately) behind the trough of the tidal wave. 



One slight irregularity will be noticed in the well-curve, as 

 drawn. This is based on one observation only, and is sufficiently 

 accounted for by the fact that two large water-barrels were at the 

 time filled by a pump connected with the well, for conveyance to an 

 adjacent farm. The fact that the quick withdrawal of nearly 

 100 gallons of water only lowered the water-level temporarily by 

 about an inch is a satisfactory proof that the well is not fed by a 

 mere small local spring, but is in free communication with a large 

 body of underground water. This is further proved by what I was 

 told respecting at least two other wells in the village (now not 

 easily accessible, else I should have tested the accuracy of the in- 

 formation), which are reported to ebb and fiow synchronously with 

 the well under examination. 



Thus it would appear that the prevalent idea that the water- 

 level in the well is highest exactly when the tide is lowest, and lowest 

 when the tide is highest, is not quite correct : the real fact being 

 that the water in the well goes on rising for no less than 3 hours 

 after high water, and ebbing for 3 hours after low water. 



I brought away with me two samples of the well-water — one 

 collected when it was at its lowest level, the other taken when 

 it was at its highest level. On subjecting them to analysis, I 

 find that there is practically no difi'erence in their composition. 

 This would seem to prove that no sea-water finds its way directly 

 into the well to cause the ebb and flow, although the large proportion 



Q. J. 0. S. No. 215. z 



