CONNEXION OF CYCLONES AND RAINFALL WITH SUN-SPOTS. 467 



1850 and 1859 to 1861 the number of cyclones was 65, whereas iix the 

 minima periods 1855 to 1857 and 1866 to 1868 it was only 34, or little 

 more than one half. In 1856 there was only one hurricane of small extent, 

 and in 1867 no hurricane at aU. Indeed it is doubtful whether several of 

 the cyclones in the latter year, classed under " storms," should not have been 

 classed under " whole erales " and " strona- gales." 



The Number of Cyclones in each year, from 1847 to 1873. 



* To 3l8t May. 



As during the last twenty-two years information respecting the cyclones 

 of the Indian Ocean has been carefully and systematically collected and tabu- 

 lated, I believe that the results now given are substantially correct ; and it 

 seems to me that they point to a close connexion between sun-spots, or 

 solar cyclones, and terrestrial cyclones, or what might be called earth-spots 

 by an observer on another planet. 



Most of the severest cyclones have been already traced, and the others will 

 also be traced. When this shall have been done, an attempt will be made to 

 express numerically the amount of cyclonic area and cyclonic force for each 

 year. The Catalogue gives little more than the number of cyclones ; but, from 

 what is already known, there is little doubt that their extent and force were 

 also far greater in the maxima than in the minima years. 



Being desirous of extending the investigation as far back as possible, I have 



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