18 $ 
RECIPROCATING SPRINGS. 
and was ob- 
structed by 
intermissions 
by air. 
This fact 
agrees with 
those of the 
irregularly 
Intermitting 
springs. 
Particular 
explanation 
of Mr. Swain 
Eton’s Appa- 
ratus, and its 
effect. 
above the brim of the boiler ; the third is a descending leg, 
which performs the office of a nozle, that is, it discharges the 
water from this crooked canal into the boiler. Mr. Swainston 
observed by accident, that when the workmen were filling 
the vessel last mentioned, the water reciprocated in the tub, 
the surface of it rising and falling alternately in a manner 
which he could not explain, by supposing some slight irregu- 
larity in the management of the pump. When the appear- 
ance was more carefully examined, he found a corresponding 
variation in the efflux at the nozle j for when the water was 
rising in the tub, the stream was perceptibly weaker at this 
outlet, than it was during the ebb or fall of the water in the 
vessel last-mentioned. He farther observed, that when 1 the 
water in the boiler rose high enough to cover the end or nozle 
of the siphon, bubbles of air were seen ascending from this 
orifice, during the ebb in the tub, or at least during the former 
part of itj but that they did not appear during the flow, or 
whilst the water was accumulating in the tub. The fluctua- 
tions here described, were far from being regular, either in 
magnitude or duration ; for the water rose much higher in the 
tub at one time, than it did at another j and the intervals 
betwixt flow and flow, or ebb and ebb, were very unequal. 
In fact the appearances seen in this vessel imitated the caprices 
and singularities of Giggleswick Well in a natural and sur- 
prising maner. 
The exact coincidence of the effects, produced by an ar- 
tificial apparatus, and a noted reciprocating fountain, will 
naturally turn the attention of the curious to inquire into the 
cause of the irregular motions, which Mr. Swainton observed 
in his reservoir. The circumstance on which these fluctua- 
tions depended, is easily understood j 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 winter, or in other words in the state of foam. Now 
it is well known, that the bubbles, constituting this frothy 
substance burst, and the air separates from the water, when 
the agitation ceases 5 by which the compound was produced. 
Such a separation would take place unavoidably in the siphon 5 
because a current flowing in a tube moves on smoothly, or 
without interruption, which is the cause of agitation. The 
process 
