226 THE WEATHER. 



the bay, there is a mountain of great elevation, called, 

 from its extended flat summit, the Table Mountain. In 

 general its rugged steeps are seen rising in a clear sky ; 

 but when the southeast wind blows, the whole summit 

 becomes enveloped in a cloud of singular density and 

 beauty. The inhabitants call the phenomenon the 

 spreading of the table-cloth. The cloud does not appear 

 to be at rest on the hill, but to be constantly rolling 

 onward from the southeast : yet, to the surprise of the 

 beholder, it^never descends, for the snowy wreaths seer, 

 falling over the precipice towards the town below, vanish 

 completely before they reach it, while others are formed 

 to replace them on the other side. The reason of the 

 phenomenon is, that the air constituting the wind from 

 the southeast, having passed over the vast southern ocean, 

 comes charged with as much invisible moisture as its 

 temperature can sustain. In rising up the side of the 

 mountain, it is rising in the atmosphere, and is therefore 

 gradually escaping from a part of the former pressure ; 

 and on attaining the summit it has dilated so much, and 

 has consequently become so much colder, that it lets go 

 a part of its moisture. This then appears as the cloud 

 BOW described : but it no sooner falls over the edge of 

 the mountain, and again descends in the atmosphere, to 

 where it is pressed, and condensed, and healed as before, 

 then it is re-dissolved and disappears : the magnificent 

 apparition thus dwelling only on the mountain top.' 



Such are the general principles by which the changes 

 of cloud and rain, sunshfhe and storm, and all 

 those meteorological phenomena which occur in the 

 atmosphere are regulated. There are, however, many 

 particular and striking results to which we should be 

 glad to direct the attention of our readers, so far as our 

 limits will permit. The subject, however, which must 

 principally attract our attention must be the effects of 

 electricity. 



4. THUNDER AND LIGHTNING. 



The various phenomena which are to be classed under 

 the head of electricity, and of which the thunder is one, 

 are very imperfectly understood. Some facts, and the 



