iiob WELLS S NATURAL PHILOSOPHY. 



to several Imndrcds, and its altitude is supposed to be 

 often upward of a mile. 



"When an observer is near to the spout, a loud hissing noise is heard, and 

 the interior of the column seems to be traversed by a rushing stream. 



Fig. 228. The successive appearances of a water- 



spout are as follows : — At first it appears to 

 be a dark cone, extending from the clouds 

 to the water; then it becomes a column 

 xmiting with the water. After continuing 

 for a httle time, the column becomes dis- 

 united, the cone reappears, and is gradually 

 drawn up into the clouds. These various 

 changes are represented in Fig. 228. It is 

 a common belief that water is sucked up by 

 the action of the spout into the clouds ; but 

 1> _^ there is reason to suppose that water rather 



^^j^'- ' :^^^^^^^'" ^"i'J- descends from the clouds, as water which 

 ^^^T^^i^^^^^J?"'^^ has fallen from a spout upon the deck of a 

 ■s^^^g^-^"^'^^,^^^;^^' vessel has been found to be fresh. There is 

 ^^^^^ no evidence, furthermore, that a continuous 



column of water exists within the whirling pillar, 



SECTION IV. 



METEORIC PHENOMENA. 



What are ^^^- Mctcorites arc luminous bodies, which 



Meteoiites? from time to time appear in the atmosphere, 

 moving with immense velocity, and remaining visible but 

 for a few moments. They are generally accompanied by 

 a luminous train, and during their progress explosions are 

 often heard. 



What are ^^5. Tlic tcrm aerolltc is given to those 



Aerolites? stouy masscs of matter which are sometimes 

 Been to fall from the atmosphere.* 



What is known The weiglit of those aerolites which have been known to 



respecting the fall from the atmosphere varie? from a few ounces to several 



weight and ve- , , , , 



locity of aero- hundred pounds, or even tons. 



^'■^' The height above the earth's surface at which they are sup- 



posed to make their appearance has been estimated to vary from 18 to 80 miles. 



• Aerolite is derived from the Greek words acp (atmosphere) and AiOoj (a stone). A 

 meteor is distinguished from an aerolite by the fact that it bursts in the atmosphere, but 

 leaves no residuum, -while the aerolite, which is supposed to be a fragment of a meteor, 

 eomes to the ground. 



