1 24 Dr. Percival on the different ^antities 



appear to be owing to any miftake, but to be the 

 regular effect of feme caufe, hitherto unnoticed. 

 The rain-gage, in one of thefe places, was fixed 

 above all the neighbouring chimnies ; the other 

 was confiderably below them : and there was 

 reafon to fufpedt, that the difference in the quan- 

 tity of rain, might be owing to the different 

 jGtuarions of the veffels, in which it was received 

 A funnel was, therefore, placed above the highefl 

 chimnies, and another upon the ground of the 

 garden, belonging to the fame houfe; and the 

 like diverfity was found between the two, thus 

 near together, which had fubfiftcd, when they 

 were fixed, at correfpondcnt heights, in different 

 parts of the town. Similar experiments were 

 rnade on Weflminfter Abbey ;* and repeated at 

 Bath, Liverpool, Middlewich, and other places, 

 with nearly uniform refuks. The obfcrvations, 

 therefore, however new and fingular, are too 

 well authenticated, to admit of the leafl degree 

 of doubt: and it is the office of philofophy to 

 furnifh an adequate and rational folution of 

 them. Dr. Heberden conjeflures that the phas- 

 nomenon depends on fome unknown property of 

 clcflricity. To me it appears probable that the 

 common laws, by which this power influences 

 the alcent and fufpenfion of vapours, are fuf- 

 ficient to explain their precipitation in rain, and 



* Pliil. Tranfaft. vol. LIX. p. 359. 



