618 Miscellaneous. [July, 



IX . — Miscellaneous. 



1. — Proportion of rain for different lunar periods at Randy, Island of Ceylon. 

 [Extract of a letter from Capt. W. R. Ord.] 



As regards this Island it may be gratifying to others to learn that through 

 the kindness and encouragement of Major General Sir John Wilson, command- 

 ing the forces, I have been enabled to commence a continuous series of two- 

 hourly registrations of the thermometer, and an hourly one once a week at this 

 station, on the principle recommended by the British Association in the 1st 

 vol. of their report, speaking of Devonport ; and a friend in Colombo has kind- 

 ly assured me he will take charge of a similar operation at that place. Thus I 

 am induced to hope that this key of Southern India may yet bear its share in 

 the promotion of science, so fine an example of which the Peninsula is spreading 

 before us. 



The highly interesting explanation of the cause of the different quantities of 

 rain falling from different heights above the ground given in the Asiatic Journal 

 No. 37, led me to calculate what the augmentation of one drop might be through 

 the respective falls, and which appears to be as follows ; namely, — 



In 1000th parts of its own diameter, a drop of rain falling to the earth at 

 York, gains, from an elevation of 



ing the warmer 

 months. 



f 



42 





During 



the year. 



56 





During the 

 colder months. 

 78 



43ifeet.. \ 



[ 



or 



of its own dia. about g ! 5 

 114 



•• 



or 



ft 



148 



•• 



or 



i 



13 



202 



213 .A 



or 





or 





or 



I 



1 



.. 



7 



.. 



% 



In order to attempt a similar experiment, with the permission of His Excel- 

 lency the Governor I have established a pluviameter and evaporator on the top 

 of the Pavilion here, at a height of about 75 feet above those at my own house, 

 and also one on a hill about 350 feet above the latter ; from which, when it is 

 considered that our climate is a perpetual summer, and our average annual fall 

 of rain nearly 80 inches, I think the result may be worthy of notice. 



For those who are interesting themselves in this subject I take the liberty of 

 adding the following remarks made through a succession of 32 lunations on th© 

 fall of rain from January 1834 to July 1836 ; within five days before the day of 

 the new moon, or in 



fall in inches. 

 176 days before new moon, .. 53325 



,, after new moon, .. 43'875 



,, intermediate, . .. 26*766 



,, before full moon, .. 33*405 



,, after full moon, .. 28- 07 



,, intermediate, .. 38* 25 



The 176 intermediate are calculated from the actual fall in the 121 and 120 

 days intervening. 



From such statements aberrating rules might perhaps be drawn ; but it would 

 appear that allowance ought to be made for extraordinary falls which arise from 

 circumstances with which we have little acquaintance, and which, as they can- 

 not be introduced into general formulae make all our calculations more or less 

 erroneous. 





comparative fall. 



or as 



100.0 



to 



82-3 





50*2 



», 



62-6 



it 



526 



»» 



717 



