136 
J. HOPKINSON-WATEE AND WATEE-SUPPLY 
following year, “On the injurious consequences likely to accrue 
to a portion of the County of Hertford if the London and West¬ 
minster Water Company should carry into effect their project of 
supplying the Metropolis with Water from the Yalley of the Eiver 
Colne;” in 1842 he contributed a paper to the Institution of Civil 
Engineers on the water-level in the Chalk under London, con¬ 
tinuing it in the following year; in 1850 he contributed another 
on the depression of the Chalk water-level under London; and in 
1876 he read a paper before our Society on the “Geology and 
Water-supply of the Neighbourhood of Watford.”* 
Before Mr. Clutterbuck commenced to publish the results of his 
investigations, the late Mr. John Dickinson established a percolation- 
gauge at Nash Mills with the object of ascertaining the amount of 
water which percolates into the Chalk, so that he might predict the 
future flow of the Eiver Gade, and so take no more orders for paper 
than he would be able to execute, the output from Messrs. Longman 
and Dickinson’s mills then being limited to the water-power of the 
river; this was in the year 1835. Earlier still, in 1833, he set up 
a rain-gauge, evidently with the same object, but he doubtless soon 
became aware that the rainfall afforded no sure guide to the future 
height of the underground water, which height determines the 
amount of perennial flow of rivers deriving almost the whole of 
their supply from springs in the Chalk. 
The investigations of the Underground Waters Committee of the 
British Association are confined to variations of water-level in wells, 
the quantity and quality of the water obtained from them, and the 
sections passed through in sinking wells and bore-holes; and the 
information furnished by the Committee in the annual Eeports of 
the British Association is derived from replies received to the 
following queries,! and occasionally from published data. I omit 
the queries which do not affect our county. 
1. Position of well or wells with which you are acquainted. 
la. Date at which the well was sunk. Has it been deepened 
since ? 
2. Approximate height of [the surface of the ground at] the 
same above the mean sea-level. 
3. Depth from surface to bottom of shaft of well, with diameter. 
Depth from surface to bottom of bore-hole, with diameter. 
3a. What is the extent and number of the horizontal drift-ways, 
if any? 
4. Height at which water stands before and after pumping. 
Number of hours elapsing before ordinary level is restored after 
pumping. 
5. Quantity capable of being pumped in gallons per day. 
* ‘Trans. Watford Nat. Hist. Soc.,’ Vol. I, p. 125. 
t The Secretary to the Committee, Mr. C. E. De Ranee, 28, Jermyn Street, 
London, S.W., will forward, on application, copies of the schedule containing 
these queries. If, after insertion of information on any one or more of the 
points referred to, the schedule is sent to me, the information will be copied for 
publication by the Society, and the schedule will be forwarded to Mr. De Ranee. 
