1835.] 



as influenced by the moon's declination. 



209 



subject, (Part 1. Trans. Phys. Class, As. Soc.) and map to accompany it. 

 In the map No. 4, we have the line of the highest high water, and of 

 highest low water in the different years, and I have transferred those 

 heights into numbers (as nearly as could be done by common measure- 

 ment), and then taken the mean of both for the mean height of the river 

 in each year during the rainy season. Recollecting then, thatthe month- 

 ly maximum declination of the moon was at its least about Michaelmas 

 1829, its greatest would be about the end of May, 1820, and its least 

 again, very early in 1811 : — and regarding the Hooghly as the 

 general rain gauge of the country*, we have the mean height of the 

 river in each season, as follows : — 



1806. 



ft- in 



1807. 



1808. 



1809. 



1810. 



1811. 



1812. 



1813. 



1814. 



it* in. 



15 10 



15 11 



15 



15 6 



14 4 



15 

 min. 

 dec. 



14 10 



13 10 



* 



14 9 



1817. 



1818. 



1819. 



1820. 



1821. 



1H22. 



1823. 



1824. 



1825. 



ft. in. 



















15 5 



16 4 



15 8 



15 9 



max. 

 declio. 

 of j). 



15 9 



16 7 



19 3 



# 



15 10 



15 5 



1815. 

 15 4 



1826. 1827 



1816. 

 14 1 



15 10 



15 



There is an irregularity in these numbers ; and both the minimum and 

 maximum height of the river appear to have occurred from two to three 

 years after the maximum declination of the moon ; but if we take the 

 average of five or seven years nearest the maximum, and compare it 

 with the average of a similar number of years nearest the minimum, 

 the difference will be striking. A curious question here arises — Have 

 we in history any record of inundations, or drought and famine corre- 

 sponding in the times of their occurrence with these different positions 

 of the moon ? I think we have. But the question is one that de- 

 mands a very wide research, much more so than, with my present 

 limited means of reference, I am able to give it; but I hope at a future 

 time to be able to lay a few items of information respecting it before 

 the Society. In my last paper, I suggested that the great abundance 

 of rain when the moon's declination was greater than 22°30' might 

 be accounted for by the locality of Calcutta, but on consulting my 

 own register, I find that a similar effect was perceptible at Dehli 

 (lat 28° 40') last year. As a sample of it, I subjoin the days in the 

 month of July on which rain fell, with the amount, and declination 

 of the moon at noon. 



* It must be remembered tbat the level of the Hooghly at Calcutta is also 

 affected materially by the tides of the Bay and by the prevailing winds of the 



season. 



-Ed. 

 D D 



