Ebbing and Floming Weil. 363 
quence of which the efflux will continue to 
encrease at the outlet, so long as the water 
continues to accumulate in the visible basin. 
3d. Now the discharge from the outlet, which 
becomes more copious every moment, being 
contrary to the influx from the siphon, which 
grows gradually weaker, the surface of the 
well will cease to rise so soon as these opposite 
powers are equal in their effects ; and the 
flow will be at the full in this instant. 4th. 
The well cannot rembin stationary, for any 
length of time, at its highest elevation; be- 
cause the vigour of the siphon being perpe- 
tually on the decline, all the water discharged 
by it will rua off through the outlet, toge- 
ther with part of that, which had been pre- 
viously accumulated in the visible fountain, 
during the time of the flow. Sth. Hence it 
is evident, that the well will begin to subside, 
the moment it becomes stationary ; after 
which it will persevere in a retrograde motion, 
until the siphon shall have emptied the sub- 
terranean reservoir. 6th. If no veins of 
water discharge themselves into the visible 
basin, besides the siphon which runs periodi- 
cally, the spring is called, an INTERMITTING 
fountain. The Bolderborn is of this kind, 
for it remains dry while the secret reservoir is 
filling, and flows while the siphon is in action. 
Zz 2 
