1836.] 



On the Revolution of the Seasons. 



285 



years prior to 1 834, there had heen a complete drought, which had 

 brought a famine upon these islands, and, in consequence, some 

 thousands of the inhabitants had died." — Sketches of Cape de Verd 

 Islands. — United Service Journal, July, 1835. As these islands lie 

 in a latitude between that of Calcutta and Madras, the fact is inter- 

 esting, but I have no accounts to refer to for the state of things 

 during that period, in the intervening countries of Egypt, Abyssinia, 

 Arabia, and Persia. 



Lastly. It will be objected, that a regularly ascending and descend- 

 ing series has not been made out. 



This is true ; but as the number of series from which to take the 

 averages has increased, so has the tendency to it become more appa- 

 rent. There is one circumstance, however, which may serve to prevent 

 a regular ascent and descent from ever becoming perceptible, viz. 

 the place of the perigee. Having been lately engaged in an examina- 

 tion of barometric heights with regard to this, I have noticed that the 

 average amount of variation from the mean, either in excess or defect, 

 is greater about the time of perigee, as it also is about that of maximum 

 declination. Now there are some years in which the day of perigee 

 coincides about the solstices with that of maximum declination, and 

 these years are usually the extreme ones, both of moisture and drought. 

 I subjoin a sample. 



Perigee 



and Max. 



NorthDecl. 



1814-1815. 

 ilcutta, 

 adras, 32.27 

 acao, 95-70 



The three numbers in the Calcutta guage are, one, the highest, and 

 two the lowest up to 1 833 ; the six numbers in the Madras guage are 

 the four minima and two maxima noted up to the same period. Of 

 the three numbers from the Macao guage, one only is an extreme, 

 but the other two are very large either way. Some other circum- 

 stances, also, would lead to the belief, that peculiar localities receive 

 the changes both of drought and moisture earlier than others. Thus 

 the last drought was at its height in Bengal in 1832, and also at 

 Madras ; but it did not reach either Delhi or the Nilgherries to the 

 westward until 1833. This of course introduces a new source of 

 confusion. 



There is one other way of attempting to trace the variation of the 

 seasons, and that is by a comparison of the prices of corn in different 

 years at different places ; but this must be deferred for the present. 





Perigee 



Perigee 



Perigee 



Perigee 



Perigee 





and Max. 



and Max. 



and Max. 



and Max. 



and Max. 





NorthDecl. 



South Decl 



South Decl. 



South Decl. 



North Decl. 





1814-1815. 



1818-1819.* 



1822-1823. 



1826-1827. 



1831-1832. 



Calcutta, 







77-2 



55-42 



50-25 



Madras, 



32.27 



77-08 27-62 



26-61 



88-67 



20-07 



Macao, 



95-70 





55-70 



51-80 





