180 Scientific Intelligence, — Heterology . 



main untouched, and its inmates, some, or all of them, as the 

 author has known to occur, perish under its scorching influence. 

 Occasionally the spindle of a ship's mast, the most elevated part 

 of it, may appear to be the point of attraction, and it will some- 

 times dart among the spars and cordage harmless, descending 

 till it reach the deck, when it suddenly quits the vessel by some 

 aperture, and rapidly returning through another, seems to have 

 acquired a new character with incredible velocity ; for, steering 

 its strange and rapid course into the maindeck or hold, it will 

 kill, maim, or injure every animate or inanimate with which it 

 comes in contact. Much good has unquestionably been effected 

 by conductors ; biit those who have watched the progress of 

 the electric fluid, will hold the theorist in no estimation, who 

 does not make the atmosphere the first and most important point 

 of consideration. The heavy peals, or rather the terrifying 

 shocks, of thunder which follow the lightning, frequently not 

 only shake the buildings at Freetown, but the very foundations 

 on which they stand ; and the reverberations from the surround- 

 ing mountains increase, if possible, the awe excited by elemen- 

 tary commotion. The succeeding rain, or rather deluge, is 

 happily of short duration, and rushing down the various inlets 

 and indentations in the adjoining mountains, it forms into streams 

 even a few minutes after its commencement, which sweeps 

 through the streets of Freetown with astonishing velocity, bear- 

 ing with them all the exposed vegetable and other matter, in a 

 state of putridity or decay. Such is the tornado, and it is by 

 the preponderating power of its gusts, and the atmospheric in- 

 fluence of lightning and its rains, that noxious exhalations from 

 the earth, and deleterious miasmata, before confined to the 

 neighbourhood of their origin by opposed or light currents of 

 air in the day, or attracted by the land (the more lofty the 

 more attractive) in the night, are removed, and consequently, 

 the indescribably distressing feelings occasioned by a foul at- 

 mosphere, are superseded by those comparatively pleasurable 

 and enlivening sensations which have been already noticed, 

 pp. 40-42. The average time for the tornados to set in, is the 

 termination of the month of September, from which time until 

 Christmas, tolerably calm weather may be expected At Christ- 

 mas, the periodical winds called the harmatan commence, and 



