Tl^ lECTUnjf LVII. 



We can, however, by no means precisely ascertain in what manner all tlie 

 electrical phenomena of the atmosphere are produced. It appears from the 

 experiments of Beccaria and Cavallo that the air is in general positively 

 electrical, and most so in cold and clear weather; in cloudy weather more slight- 

 ly: and that during rain, the air is generally in a negative state. Mr. Read 

 has found that air charged with putrid vapours of any kind, and in particular 

 the air of close rooms, is almost always negatively electrified. The electri- 

 city is more readily communicated to an electrometer in an elevated situation, 

 and in damp weather, than in other circumstances; a candle is also very 

 useful in collecting it. When a wire is connected with a kite, being con- 

 tinued along the string, we may frequently obtain from it sparks a quarter 

 of an inch long. 



We find a complete and interesting description of the effects of a violent 

 thunder storm in a paper by Mr. Brereton, insertf^d in the Philosophical 

 Transactions. The circumstance happened in September 1780, at East 

 liourn, in a house occupied by Mr. Adair: it was built of stone, and stood 

 facing the sea. About nine o'clock, in a very stormy morning, a black cloud 

 approached the house ; several balls of fire were seen to drop from it succes- 

 sively into the sea, and one in particular, appearing like an immense sky 

 rocket, broke against the front of the house in diiferent directions. Mr. 

 Adair was standing at a window on the first floor, with his hands clasped 

 together, and extended against the middle of the frame; his hands were 

 forced asunder, he was thrown several yards off on the floor, and remained 

 for some time speechless and motionless, although not insensible: his clothes 

 were much torn ; several articles of metal about his person were partially 

 melted, while others, apparently in similar circumstances, and in particular 

 a silver buckle, escaped; and his skin was in many parts much scorched and 

 lacerated. The whole of the glass in the window, and a pier glass near it, 

 were completely destroyed, and scattered about the room; most of the fur- 

 niture was broken to pieces, and all the bell wires were melted. In the 

 room above this, a lady and her maid were driven to a distant part, and 

 rendered insensible for some time, but not hurt; in the room below, two 

 servants, who were near the wnndows, were struck dead : both the bodies were 

 turned black; one of them had a wound near the heart; and neither of theih 

 became stilf after death; a third servant, who was a little behind one of them, 



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