pg^ Obftrvaticns en the Fotmotion aiiJ 



raifes the vapours through the watcr-fpout to the cloud ? Simply to afiirm that this agent U 

 tleflricity, without further proof, is in fa£l to fay notliing. To this queilion I mull anfwer, 

 that 1 have exhibited the producfls of obfcrvation : I have related what I have mod clearly 

 feen. I tliink I can difcern the caufe without being able to exhibit proof : but I fliall be 

 happy to be anticipated by philofophcrs of greater (kill in this theory, and think it better to 

 fufpend my judgment than yield to the fedu£live pleafure of explaining every thing by adding 

 to the mafs of error in natural philofophy. 



The fccond faft which pvefents itfelf in our obfervatlons is, that two caufes unite in the 

 formation of water- fpouts, or rather two different modifications of the fame caufe. When 

 the foot appears without the water-fpout, it is not the producklve caufe, but rather an effer- 

 vefcence which prevails iq the fca at that place. But how many intereftingqucftions might 

 be afked refpefting this part of the phenomenon ! What caufe is it fo powerful as to retain 

 the foot a, fig. 3, and keep it motionlefs,notwithftanding an impetuous eafterly wind, until 

 the projeclion in the cloud which is to form the water-fpout fliall arrive direftly over it ? 

 Was the apparent bag which developed itfelf from the cloud, pre-exiftent in the projei.llng 

 part ? As I can make no fatisfadory reply to thefc and other queftions which might be 

 propofed, I fliall proceed to the third remarkable faifl. 



3. When the foot of a water-fpout begins to approach the earth, its diameter contraiSls, 

 its height is diminiflied, and its volume becomes lefs and Icfs ; fo that the foot is reduced to 

 nothing at the inftant it touches the fliore. From the attentive examination I have made, it 

 has appeared that the foot even of the greatefb water-fpouts began to dlminlfli when the 

 depth of the fea beneath became lefs than the elevation of the foot Itfelf above the furface. 

 If this be true, as I think it is, it may be concluded that the effervefcence which fupplles the 

 fpout with water, and forms the furrounding vapours of the foot, extends itfelf in depth 

 nearly as much as the foot itfelf rifes above the fca, and that materials for the fupply of 

 v.ipour become defedive in quantity in proportion to the fhallownefs of the water. 



Explanation of the Drawing. 



FIG. I. Plate XXIV. reprefents the lmperfc<SV foot a of the water-fpout feen on the 6th 

 of Janu.iry 1789, at five minutes after ten in the morning. On the left hand are feen the 

 clouds which rife towards the zenith, but (till confiderably diftant. This foot had plumes 

 elevated nearly like fails, and was driven towards the fliore by the wind. In proportion as 

 it came near the land it contrafted, and was reduced into a column of mift, which the 

 wind ovcrfct on the land the moment the fupply of water was wanting. 



Fig. 2 reprefents, letter a, the enormous water-fpout obferved on the fame day at eight 

 minutes before noon. Nothing could more nearly refemble a fliip of war on fire than this 

 phenomenon, excepting that no flames appeared. I have endeavoured to fliew the con- 

 tinual jets of its furrounding vapour, and of the water wiiich Iflued from the centre. At b 

 are feen the remains of a water-fpout after it has been dcflroyed by the foot having touched 

 the ground. 



Fig. 7. Plate XXV. a reprefents the foot of the fecond water-fpout ready formed, which 

 was probably the third. It has yet no fpout. At b is feen a protuberance tending obliquely 

 towards tlie call, and advancing to the weft with the cloud to which it is fufpcndcd. At 



the 



