Apptar/irifcs of JFater-Spouls. , . 583 



viliich mull feparatefrefh. water from the fait ; it being afcertained by experiment, that 

 dillillation is the only msihod by which fea-water can be rendered completely freih. 



I fliall take the liberty in this place to make ufe of a comparifou, by way of explaining 

 more perfe£lly the phenomenon we at that time beheld. It will net probably be unac- 

 ceptable to fuch as have never feen a water-fpout, at leaftrin fo favourable a poCtion. bup- 

 pofe tlis chiinney of a baker's oven, fuch as we have at Nice, in which the fuel commonly 

 burned confifts of branches of pine recenily broken from the tree, and fuflicient to bake 

 large quantities-of bread ; let this chipiney be imagined to be in the ftate of throwing out 

 immcnfe clouds of xfapourand finoke. Suppofe a funnel of glafs to be adapted to tlie 

 aperture at the lower part, and to have its diameter enlarged upwards, until it terminates 

 in a very extended vefltl. It may eafily be conceived that the afcending vapours will be fo 

 prefled together in the narrow neck of the glafs, as to render it opake, without permitting 

 the fuccefllvc undulations of the vapour to be difcerned. But in proportion as they pro- 

 ceed further fiom the caufe of motion, which is the fire of the oven, and arrive at a part 

 of the glafs where they have room to expand, the vapours, being lefs condenfed, will exhi- 

 bit their peculiar motions, and the fucceffive eruptions of the fmoke will indubitably be 

 feen. In this imaginary experiment, let the foot be fuppofed to be abftratled ; let the af- 

 cending vapour be fimply that of boiling water, and the conical tube of glafs here con- 

 templated, will afford a natural reprefentation of the phenomenon obferved in 1780, and 

 confirmed on the 6th of January 1789. 



It may perhaps be objected, that thefe facts do not at all agree with Profefibr Mufchen- 

 broek's theory of water-fpouts, given in Jiis Elfai de Phyfique. This objeclion was darted 

 by all my philofophieal acq-uaintance againftthe report of our obfervation in 1780, and en- 

 gaged me to fufpend the publication of my memoir for feveral years, becaufe it was not 

 poffible to reconcile the means employed by nature in the produfiion of water-fpoiKs, nor 

 their ufe, with the ideas of the celebrated Dutch Profeflbr. Befides which, having only one 

 obfervation to cfFer, though well fupported by the teftiniony of two refpe(Slable perfons, I 

 flattered myfelf that I might remove all the difficulties by reprefenting a water-fpout in the 

 fame manner as lightning and thunder are imitated by the cleflrical machine. For it 

 feemed to me at that time, and ftill appears to be, a thing very pradlicable. But at pre- 

 fent, by a new feries of obfervations in confirmation of that of 1780, I fee clearly that the 

 procefles of nature are very different from thofe pointed out by Profeflbr Mufchenbroek. 

 That enlightened and mod accurate obfcrverhad no opportunity of examining this pheno- 

 menon in a favourable pofition himfelf, and has been equally unfortunate in the explanation 

 of the fuppofed defcent of water, which really afcendj in water-fpouts, as well as in the for- 

 matwn of the foot, which according to his theory is a mafs of fea-water in its natural 

 ftate. I can affirm without fear of contradidion by experience, that this foot or atmo- 

 fpherc as it may be called is nothing but the matter of clouds and miffs. 



It muft moreover be remarked, that in the time of Mufclicnbroek the theory of elecftri- 

 city had made fo little progrefs, that he did not avail himfelf of it in the account of fiery 

 meteors. It is therefore lefs wonderful that he fhould not have recurred to it in his theory 

 of water-fpouts. 



What then is the agent, it may be afkcd, which caufcs this ebullition in the fca, and 



raifes 



