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On Certain Meteorological Coincidences. 6 



In lunations, then, there are jjnder ^ '' 



(a) 16 accordant entirely; 15 discordant more or less; 



{b) 7 do, . 6 ♦ ''do, . -^ 



(c) 5 do. 1 " do. ^ ^ 



(rf) do. 1 .^, do. 



F 



28 accordant throughout; 22 discordant more or less; 



, and the chances would be in every 100 times, 56 in favor of the 

 ^ supposed rule and 44 against it ; or the final probability would 

 be 1,27, etc. : 1, for the rule. 



But this comparison by lunations is defective ; inasmuch as it 

 does not allow a distinction in the character and deeree of the 

 niscordances. For this, as well as for the proporticm of missing 

 observations, it i^ better to make comparison by the actual epochs 

 or quarter-days ; designating separately the aggregate number of 

 ^ those which coincide with the term-days, of those which differ, 

 and of those which have failed to be observed at all. Of coursfe, 

 every such epoch affords occasion for a coincidence : and in pro- 

 portion to the number of actual coincidences out of a given num- 

 ber of such occasions will be the probability of the supposed rule. 

 Counting, then, by epochs, the aggregate are as under: 



!► Accordant Discordant. Not Observed. 



(a) . . 98 26 



v^ (6) . . 31 6 12 



(c) . .10 2 ' 12 



{d) . . 1 3 



139 34 27 



If we leave the epochs not observed out of the question, the 

 chances stand as rather more than 4 to 1 in favor of the rule ; or 

 its probability is a little more than f. 



If we consider that among those unobserved epochs the chances 



of coincidence are even, then they will stand as 76 25 out of 



t 100 in favor of the rule; or its probability is rather more than 



The lowest of these probabilities is greater than is sometimes 

 taken as sufficient ground for human belief or human actions. 



1 may terminate this notice in the words of Carlini upon asimi- 



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lar occasion :* " Queste conclusion! nou devono considerarsi 



come quelle che converebbe dedurre dal paragone delle osserva- 

 zioni conlinuate per un gran numero d'anni. Cio nulla ostante, 

 non ci e sembrato del tulto inutile il presentar qui i risultati delle 

 poche osservazioni delle quali potevamo far uso; sperando che da 

 essi possa trarsi qualche norma par istabilire un piano generale 

 d'osservazioni meteorologiche che riesca il piu opportune alio 

 studio de' fenomeni atmosferici," 



* Sidla Legge delle Variazoni Orarit del Bar&inetrOy etc., Modena, 1848, 



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