Mr. Main on the Phenomena of Waterspouts. 1 IS 



and when exhausted, the lower end becomes broken, less de- 

 fined, and shrinking as it were upwards, disappears as it began. 



Some travellers have reported, that water-spouts rise out of 

 the sea; having observed them, perhaps, only when the spout 

 had descended and was in contact with the surface ; or it might 

 happen, that in such a case the tornado might be first generated 

 below ; and before the clouds were acted on, a column of spray 

 would be seen to rise and approach the clouds, before a co- 

 lumn of water is formed in them of sufficient density to de- 

 scend. Similar appearances are sometimes seen on shore, when 

 columns of dust, or, as the writer has often witnessed, even 

 cocks of hay are carried up into the air by whirlwinds to a 

 great height. 



So frequent were these meteorous appearances during this 

 part of the voyage, that on one occasion (when in sight of 

 " The Rabbit and Coney," two small islands in the Straits, well 

 known to navigators), no less than five water-spouts were seen 

 from the ship at the same instant ! some of which were falling 

 on the land, and others on the sea ; — the nearest to the ship 

 being computed to be at the distance of five miles. The writer, 

 who attentively observed these phaenomena, used an excellent 

 perspective glass, and on one occasion had an opportunity of 

 seeing one while the sun shone upon it (about 7 a.m.), which 

 appeared to be tubular ; as the sun's rays were reflected in a 

 double parallel stripe along that part of the spout on which 

 they shone, viz. one stripe reflected from the exterior side next 

 the sun, and another less bright from the interior surface (as 

 was supposed) of the opposite side. This, however, is only a 

 surmise ; but from similar motions of fluids which may be seen 

 at any time, there may be reason for supposing that the spout 

 is not solid : for instance, if a hole be made in the bottom of 

 any vessel, and plugged up with the end of a stick ; let the 

 vessel be filled with water and the plug withdrawn, the water 

 in escaping through the aperture soon assumes a circular or 

 rather a spiral motion, the descending column draws, or more 

 properly speaking, admits after it an inverted cone of air, 

 reaching from the surface of the water to the hole at which it 

 escapes. 



The idea of preventing the approach (for these phaenomena 

 are seldom stationary) of a water-spout upon a ship (which 

 might produce dreadful consequences), by discharging great 

 guns towards it, is reasonable ; and if it did not approach too 

 rapidly, no doubt would be effectual ; because the concussion 

 from the gun would counteract and break the sweeping cur- 

 rent of the tornado, and thereby dissipate the motion-em- 

 bodied fluid, and of course prevent its effects. 



Q 2 Many 



