lx 
PROCEEDINGS OF THE 
that 3 feet was sufficient depth to gauge the water which gets 
heyond the reach of capillary action and possible subsequent 
evaporation from the surface. But that was not at all the case. 
They had not a greater authority on this subject than the late 
Professor Ansted, and he made experiments which showed that 
water was actually drawn up through chalk by capillary action 
a distance of 16 feet, and he came to the conclusion that there 
was no practical limit to the depth from which water might be 
thus drawn up. Much water which percolates through the surface- 
soil in the winter was very probably—and experiments had been 
made which tended to show it—drawn up again in the summer 
when the ground gets dry; the continual capillary action bringing 
the water to the surface to be evaporated, and not only evaporated, 
but absorbed by vegetation. This showed one important point 
which had not been thoroughly considered, and that was, how far 
the moisture necessary for the success of agricultural operations 
on the Chalk, in the summer, in dry times, to supply the amount 
required by growing crops, is dependent upon the winter rainfall 
rising by capillary action. No doubt a great amount was so drawn 
up from a considerable depth and absorbed by vegetation. Another 
point was the extent, in Hertfordshire, of woods. It was well 
known that in a wooded country, by evaporation from the leaves 
of trees cooling the atmosphere and thus causing condensation of 
vapour, there is a greater rainfall than in a treeless country,— 
that more rain falls where there are many trees than where 
there are few trees. But a series of experiments were made at 
one time which proved that an oak tree would absorb more than 
eight times as much water as fell upon it during the period of 
its summer growth, showing to what a great extent we are depen¬ 
dent for the favourable state of our crops, and vegetation generally, 
on the amount of rain which falls in the winter and gets down 
to the underground reservoir to be drawn up again in the summer. 
With vegetation, also, he thought that the percolation through 
a heavy soil would be less than that through a light soil. 
Dr. Brett said that the late Bev. James Clutterbuck, who was born 
at Watford House, where his father, the historian of Hertfordshire, 
lived, took a great interest in the water question fifty years ago, 
when he was curate at Watford. He spent much time and labour in 
taking observations on the level of water in wells, and in studying 
the geology as affecting water-supply. He might indeed be called 
the father of hydro-geology, at least in Hertfordshire. He (Dr. 
Brett) had received many letters from him on the subject. He 
had one written about ten years ago, when he asked him the 
best way of increasing the Watford water-supply, which was 
failing, possibly because the North-Western Bailway Company 
had sunk a well by the viaduct and were taking a large quantity 
of water, and the brewers also were using a good deal. In that 
letter, which was dated “June 6, 1881,” he said: “I have always 
maintained that the water in the Chalk is exhaustible, though I 
may have said that the quantity taken to supply the town of 
