1819.] Days of Rain, Snow, and Drizzle, at Viviers. 109 



Meteorologists do not appear to me to have taken into their 

 account the water which remains attached to the sides of the 

 gauge after they have emptied it. To determine its amount, I 

 weighed the instrument while dry, I then moistened it in the inside 

 with rain water, and after allowing the water to run out, I weighed 

 it again. The weight was increased by 87 gr. (the mean of seve- 

 ral trials). Now 8/4-5 : 87 :: 1 cubic inch : 0-2323 cubic inch. 

 This last is the amount of the rain retained by the gauge, which 

 corresponds to 0*074 1 line in height, or nearly -^th of a line. I 

 always added this last quantity to all the measures of rain. This 

 water, which remains attached to the gauge, ought not to be 

 neglected, since in a whole year, supposing 98 days of rain, it 

 amounts to more than 7*25 lines. The whole height of the rain 

 water which has fallen at Viviers in the course of 4U years; 

 namely, between 1777 and 1818, amounts to 113 feet 3 inches 

 and 4 lines. This quantity, divided by 40, gives 33 inches 11-8 

 lines, for the mean height of the rain which fell each year ; and 

 this quantity is divided among the months of the year in the 

 following manner : 



Inches. 



January 2 



February 



March 



April . ■ 



May 



June 



1 

 1 

 2 

 2 

 2 



Lines. 



5-73 



8-46 

 11-13 



8-23 

 11-17 



6-75 



Inches. Lines. 



July 1 10-59 



August 2 4-17 



September 4 1*68 



October 4 8-89 



November 4 2-24 



December 2 4-76 



If we took the mean annual quantity of rain for unity, we shall 

 find the mean monthly quantity as follows : 



Winter 0-1798 



C January 



0-0729 



{ February 0-0502 



I March 0-0567 



f April 0-0790 



Spring 0-2407 -J May 0-0860 



Uune 0-0757 



0-4205 



fJuly 0-0553 



Summer 0-2462 < August 0*0691 



L September 0-1218 



fOctober 0-1395 



Winter 0-3333^ November 0-1232 



(.December 0-0706 



0-5795 



rain gauzcl I detached a prism ofsnow, the base of which was a square of six inches 

 the side, from the snow winch had fallen iu the court, and measured the water 

 which it yielded when melted. 



