HERTFORDSHIRE NATURAL HISTORY SOCIETY. 
XXXV 
At tlie conclnsion of a highly interesting three hours’ walk the 
members returned to the laboratory, on the lawn in front of which 
tea was awaiting them. With appetites sharpened by the after¬ 
noon’s exercise, the visitors unanimously and unceremoniously, 
without any assistance from Dr. Gilbert, undertook an interesting 
practical experiment on their own account, and had the satisfaction 
of seeing their efforts rewarded with success. During tea Mr. 
Silvester rose and proposed a hearty vote of thanks to Dr. Gilbert 
for the instructive information he had imparted, and asked him to 
convey the thanks of the members of the Society to Sir John Lawes 
for his kindness in providing the tea. Mr. A. M. Brown, of Tring, 
seconded the vote of thanks, and Dr. Gilbert suitably replied. 
[Field Meeting, 14th June, 1890. 
THE BARTON HILLS. 
The party, which was not a very large one, journeyed from St. 
Albans to Darlington by railway. 
Shortly after leaving the station, the Manor House, a mediaeval 
structure, was visited. It is said that John Bunyan was brought 
here after having been captured in the neighbourhood, and that a 
trial took place in the house before “ the Glorious Dreamer ” was 
sent to Bedford. A small dark compartment in the roof was shown 
as the chamber in which Bunyan was imprisoned. 
The walk being resumed, led through picturesque Bedfordshire 
villages and hamlets along the Gault plain at the foot of the Chalk 
hills. Luncheon was partaken of in a field, and then the party 
walked through some pretty woodland glades by the side of a clear 
stream flowing from the Chalk, and along meadow-paths to the 
Vicarage at Barton-in-the-Clay, the charming gardens of which 
were visited. The Chalk escarpment was then ascended to a spot 
where the curious fly-orchis grows. The Barton springs next 
attracted attention, a considerable body of water flowing from the 
hill side at the bottom of a picturesque “ coombe ” or valley. The 
view from the top of the escarpment was very fine, away in the 
distance being Wrest Park House, at the foot of the downs the 
village of Barton, while the nearer prospect was composed of 
the Chalk hills with their rounded contours. 
Ravensburgh Castle, an earthwork said to have been a Roman 
summer camp, was next visited; and, assembled at the foot of the 
earthwork, Mr. J. Saunders, of Luton, made a few remarks on the 
geology of the neighbourhood. He said it was generally stated 
that the springs issued from the hills just above the hard bed of 
Totternhoe Stone, but observation led him to conclude that this 
was not the case, but that the water issued from the top of the 
Chalk Marl, which was a clayey, impervious bed, through which 
water could not penetrate. Referring to the strata in ascending 
order, he pointed out that towards the north near Ampthill they 
had an outcrop of the Oxford Clay; above that was the Lower 
Greensand; at Harlington they found the Gault; and at the foot 
