ESSEX FIELD CLUB.—REPORTS OF 
MEETINGS. 
EXCURSION TO THE CROYDON BOURNE 
448TH MEETING). 
SATURDAY, IOTH APRIL 1915. 
This was the first of a series of extra-territorial excursions imposed 
upon the Club by reason of the military occupation of our own County* 
which prohibited freedom of movement in the occupied districts, and was 
undertaken in conjunction with the Geologists’Association. Just over 
30 members of the two societies attended, and several members of the 
Croydon Natural History Society were also present by invitation. 
Mr. W. Whitaker, B.A., F.R.S., F.G.S., acted as conductor and 
favoured the party with several instructive lecturettes at various points en 
route upon “ bournes ”in general, and the Croydon Bourne in particular. 
On leaving Woldingham station, he remarked that the valley which 
we were about to descend was normally a dry waterless chalk-valley, 
with, however, a thin scattering of flint-gravel in the bottom ; and the 
question at once arose, How did the gravel come there ? The explanation 
was that a stream of some amount of erosive power must have 
occupied the valley, in times of greater rainfall than the present; and 
that the Croydon Bourne was but a diminished and periodic 
representative of this erstwhile larger and persistent stream. “ Bourne 
is one of several local names applied by custom to intermittent streams 
which appear occasionally in chalk or limestone districts in various coun¬ 
ties, and convert, for the time being, a dry valley into a swampy water¬ 
course. Bournes were known in Surrey, in Kent, in Hertfordshire, small 
ones occur in Essex, while in Dorset, Hants, and Wiltshire they were 
numerous, as well as in Yorkshire and elsewhere. Formerly regarded as 
prognostics of evil, and hence called “ woe-waters ” by the superstitious, 
their sudden appearance was now recognised as being due to a previous 
period of exceptionally-heavy rainfall, which caused the “ plane of satura¬ 
tion ” in the chalk or limestone rocks of the district to become raised to a 
height sufficient to allow the water to break out on the side of a valley, 
probably at some point where a looser texture of the rock, or a multi¬ 
plicity of joints, allowed of easy exit for the pent-up water. 
The earlier geologists believed that huge underground caverns acted 
as reservoirs for the water, and that these became emptied periodically 
by syphonic action ; but Mr. Whitaker regarded this as an untenable 
hypothesis, since it would require a separate reservoir for each one of the 
hundreds of bournes known to exist. 
At Bughill Farm, near Woldingham station, the highest point at which 
the Croydon Bourne has been known to rise, the ground was now perfectly 
dry, although the bourne had reached as far up the valley as this point a 
month ago, when at its greatest flow. The dry stream-course was followed 
down from here (the grass thickly coated with a white limy deposit), 
becoming more and more swampy, until, at Wapses Lodge, a shallow pool, 
some 50 feet across, marked approximately the present and more usual 
extreme limit of the Bourne. On 3rd March last, 3,500,000 gallons a 
