578 NAUSCOPIE FURTHER ILLUSTRATED. 



slightest connection between these appearances (revolutions) in the 

 atmosphere and floating substances at a distance. 



The knowledge I have acquired respecting the number of vessels 

 has not yet extended so far as to form a calculation with mathemati- 

 cal precision. Thus far I have been able to extend the science : 



I can distinguish with infallibility when there is only one 

 vessel, and I never can by any means announce the approach of 

 several vessels when there is only one at sea. I am too well 

 acquainted with the meteor to apprehend making any mistake on 

 that head. 



When there are several vessels at a short distance from each other, 

 I can form a conjecture, from the bulk and shape of the meteor, of 

 what number they consist. I cannot absolutely state the number, 

 because their characteristic features (traits), although separate, never- 

 theless, in consequence of their being multiplied, cause a confusion 

 which has hitherto baffled my calculations. But if I am mistaken as 

 to the precise number, I cannot be mistaken as to the mass ; and 

 whenever I announce several vessels, it is absolutely certain that 

 there are several. 



The announcements I made to the governor of the Isle of France, 

 in the month of August, 17&2, exhibit a striking proof of this dis- 

 tinction : 



On the 21st I announced some vessels ; on the 22d at noon, I de- 

 clared several vessels on the 23d I announced many, that is to say, 

 a fleet. 



Whence arose this variation ? Because at first, only nine or ten 

 vessels had come within the sphere of my observation (etoient entres 

 dans ma circonference) ; but on the 22d and 23d, other vessels had 

 appeared in the same situation (dans les memes eaux) ; then this assem- 

 blage that shewed itself successively announced to me the presence 

 of a fleet ; and such was in reality the fact. 



That absolute precision, however, which I do not pretend to 

 have yet attained, is far from being impossible ; it even appears the 

 natural consequence of the principle which I have pointed out. As 

 there is no vessel that does not carry its satellite along with it, and as 

 each vessel supplies its contingent to the general mass, all that is re- 

 quired is to examine with extreme attention the features appertaining 

 to each vessel, in order to calculate the number with precision. 



The same reason which manifests to the land the approach of a 

 vessel, exhibits also to vessels the approach of other vessels, at dis- 

 tances more or less remote, according to the state of the weather. 

 Before my voyage from the Isle of France to Brest, I had formed no 

 certain opinions respecting this conformity, in consequence of not 

 knowing whether the proximity of a vessel produced upon ano- 

 ther vessel the same effect as the proximity of the land, but experi- 

 ence has convinced me that the effects are similar. During my voy- 

 age I obtained incontestable proofs of the fact, which were registered 

 in the log-book. 



Whenever the indication was manifested, it never led me into 

 error. Twenty-seven appearances of the meteor announced to me 

 the approach of twenty-seven vessels ; and during the voyage we 



