254 Mr Black 07i the Climate 



very satisfactory examples of the important part which the elec- 

 tric fluid performs in meteorological phenomena, especially when 

 the constitution of the cloudless sky of summer began to be de- 

 ranged. As this change happened on the coasts of Albania 

 and the Morea, it commenced by the north-east winds getting 

 stronger, and veering more about from one point to another, 

 with corresponding variations of temperature. A calm, alter- 

 nated with faint southerly breezes, succeeded, which was fol- 

 lowed by a thick atmosphere at sunset, lightning over the Mo- 

 rea, and rain after which it cleared up, and a north-west wind 

 steadily prevailed. A few days afterwards off the Bay of Pre- 

 vesa, the northerly wind fell, the atmosphere thickened, and the 

 wind again sprang up from the south-east, light at first, and 

 freshed through the night. About the following sunrise, in- 

 side the Corfu Channel, one of the most terrific thunder storms 

 commenced that can well be imagined ; which, after floods of 

 rain, lasting, with slight intermissions, for several hours, termi- 

 nated by a sudden change of wind to the northward, and soon 

 afterwards a clear, cool atmosphere succeeded, with the wind 

 from the north-west for some days. 



Though more or less varied, the summer seasons, as I have 

 before remarked, always break up in the above manner, and sub- 

 side into a cool temperature. Whatever occasions the change 

 of wind, whether it be from the land becoming a greater rever- 

 berator of the solar heat, arising from the decay of its verdure 

 and foliage, and so rarefying greatly the superincumbent stra- 

 tum of air, by which the cooler currents from the sea are elicited, 

 it is very evident that the phenomena, described as attending 

 such changes of weather, result proximately from the collision 

 of clouds or strata of vapour differently electrified as to each 

 other, or from the electric condition of the clouds being in a mi- 

 nus or plus state, as respects the subjacent land and mountains. 

 For the better understanding of what takes place during these 

 electric collisions, it is necessary to ascertain what respective 

 body of clouds is plus or minus electrified ; or whether it is the 

 high land, or the atmospheric stratum impinged against it by 

 the Sirocco, which gives or receives electricity during the resto- 

 ration of that equilibrium which ensues. The experiments 

 which have shewn the negative electric state of the Sirocco, are 



