184 
RECIPROCATING SPRINGS, 
J3ut the Gig-^ the writers already quoted. I made a visit to Giggleswiek 
d^ociTJiot agree Well* in the autumn of 1 JgQ - } which taught me to value this 
with that the- once favourite theory not so highly, and in particular to dispute 
or ^' the universality of its application. The causes of these doubts 
will be easily perceived from the following description of the 
well and its operations. 
Description of This s P r ‘ n g ^' es at the foot of Giggleswiek Scar, which is a 
this last well, hill of limestone in the West Riding of Yorkshire. The wa- 
ter discharged by it, falls immediately into a stone trough 5 in 
the front of which are two holes near the bottom j these are 
the outlets of two streams, that flow constantly from the arti- 
ficial cistern. An oblong 'notch is also cut in the same side of 
the trough 1 which extends from the brim of it, neatly to 
the level of the two holes already mentioned. This aperture 
is intended to shew the fluctuations of the well : for the 
water subsides in it when the stream issuing from the rock be- 
fcpmes languid ) on the contrary the surface of the water rises 
again in the notch, so soon as the influx into the trough be- 
ver ?C if4° C uiar S £’ ns -° more copious. The reciprocations of the spring are 
“ ’ easily observed by this contrivance ; and they appear to be very 
irregular both in respect of duration and magnitude. For the 
interval of time betwixt any two succeeding flows, is sometimes 
greater, and at other times less, than a similar interval which 
the observer may happen to take for his standard cf comparison. 
The rise of the water in the cistern, during the time pf the 
well’s flowing, is also equally uncertain : for it varies from one 
inch, to nine or ten inches, in the course of a few reciproca- 
saddischarges tions. It is necessary to remark on the present occasion, that 
4r bubbks. S p r j n g discharges bubbles of air, more or less copiously intQ 
the Irpugh ^ these appear in the greatest abundance at the cora- 
rnencement of a flow, and cease during the ebb, or at least issue 
from the rock very sparingly at that time. In fact, the appear- 
ance and disappearance of these bubbles, are circumsHftices 
equally inconstant with the rise and fall of the water. 
The irregularites exhibited by the ebbing and flowing well, 
during my short visit, diminished the respect which I orpjerly 
bad for the popular theory, more especially when considered as 
a general explanation of reciprocating springs. This change of 
opinion was suggested by the caprices of the well $ which were 
top piany and too singular to be ascribed to the uniform opera- 
tion 
