Ebbing and Flowing Well. 375 
reciprocating fountain, will naturally turn the 
attention of the curious to inquire into the 
cause of the irregular motions, which Mr. 
Swainston observed in his reservoir. The cir- 
cumstance on which these fluctuations de- 
pended, -is easily understood; for, seeing the 
inverted siphon discharged bubbles of air 
occasionally into the boiler, it is manifest that 
this subtle fluid entered the tube, mixed with 
the water, or in other words in the state of 
foam. Now it is well known, that the bub- 
bles, constituting this frothy substance burst, 
‘and the air separates from the water, when 
the agitation ceases ; by which the compound 
was produced. Such a separation would take 
place unavoidably in the siphon; because a 
current flowing in a tube moves on smoothly, 
or without interruption which is the cause 
of agitation. The process here described, 
discovers the nature of the phenomena which 
are exhibited by Mr. Swainston’s vessel; for 
the air, which separates from the water in the 
siphon, is collected in some part of that tube, 
most probably in a bend connecting two adja- 
cent legs; where it forms a bubble or mass, 
large enough to produce a considerable ob- 
struction in the current, by contracting the 
area of the pipe. The water will evidently 
rise in the tub, so long as its efflux is inter- 
