Proceedings of the British Association, 113 



c On the amount of rain which had fallen, with the different 

 winds, at Toomavara, Limerick, during five consecutive years/ by 

 the Rev. T. Knox. — Dr. Lloyd said, that he had already brought 

 before the Section, at a former meeting, the results of these observa- 

 tions, while in progress; he had now the pleasure, at Mr. Knox's 

 desire, of submitting the conclusions derived from the entire and 

 completed series of five years' uninterrupted observations. After 

 explaining briefly the principle of the instrument, by which the 

 amount of rain with different winds is measured by Mr. Knox, and 

 the mode in which the results are graphically represented, he pro- 

 ceeded to read the following remarks by Mr. Knox : — Taking the 

 average monthly rain at three inches, the first six months of the 

 year are below the average, the other six months above it. November 

 and July are by far the two wettest months in the year ; and in each, 

 the greatest amount of rain is from SW. April is much the driest 

 month ; and there is nearly as much rain in it from the northern 

 portion of the compass as from the southern. With regard to the 

 gross amount which fell from each point in the entire year, that which 

 fell from S., SW., and W., is much above the average ; from the 

 other points it is below it. If the polygon which characterizes the 

 yearly rain be divided by a line running NE. and SW., then the 

 rain at equal intervals on either side of this line is equal to all, but a 

 fraction of an inch. This is the more remarkable, as these two 

 points had been fixed on by Prof. Dove as being the points of 

 greatest and least barometric pressure ; that is to say, the wind being 

 supposed at SW., any shift of it either towards S. or W. produces 

 a rise of the barometer, and also any shift on either side of NE. a 

 corresponding fall. Now, in the rain, the greatest amount is from 

 SW., corresponding with the least height of the barometer ; the 

 least is from NE., where also the barometer is highest ; and on 

 either side of this line it varies regularly. For instance, the amounts 

 from W. and S. are nearly equal, and both less than that from SW., 

 NW. and SE., are also equal, but still less ; and so on. There is 

 one particular in which this separation of the gross amount of rain 

 into the eight portions, as brought by different winds, may be use- 

 ful ; — viz. in ascertaining the respective specific gravities, and the 

 amount of saline matter brought from each direction. This may be 



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