94 SPRINGS; RIVERS, CANALS, LAKES, 



another; 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 

 'Tiatur?! and surprising manner. 



The exact coincidence of the effects, produced by an artificial 

 apparatus, and a nottd reciprocating fountain will naturally turn 

 the attention of the curious to inquire into the cause of the irreini- 

 lar motions, which Mr. Swainston observed in his reservoir. The 

 circumstance on which these fluctuations depended, is easily under, 

 stood ; tor, 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 stale 

 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; 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 interrup- 

 tion, which is the cause of agitation. The process lucre 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 adjacent legs ; where it forms a bubble or 

 mass, large enough to produce a considerable obstruction in the cur- 

 rent, by contracting the area of the pipe. The water will e\ identiy 

 rise in the tub, so long as its etilux is interrupted by t'uis obstruc- 

 tion ; but the action of the stream in the siphon will push the mass 

 of air from place to place in its own direction until it shall be dis- 

 charged at the iiozlr. The removal of this impediment will restore 

 the stream to its full vigour ; upon which the water will begin to 

 subside in the tub ; and it will continue to do so, until the surface 

 arrives at its proper level; unless a second collection of air happens 

 to be formed in the mean time. We have now investigated the 

 nature of the reciprocation, observable in Mr. Swainston's appara- 

 tus, it proceeds entirely from the obstruction of air bubbles, lodged 

 in the crooked canal ; the formation of which depends on causes 

 that act in a fortuitous or irregular manner 3 consequently the 

 reciprocation which results from their united operations will prove 

 to be equally uncertain and variable. 



Should the preceding theory of an ebbing and flowing vessel 



