FALLS OP RAIN IN CUMBEBLAND. 



205 



Here we see that whilst Round Close, which is 384 feet 

 higher than High-street, receives only about the same quan- 

 tity of rain that that place doe.s, either in the wet months 

 or in the year — -Seathwaite, which is only 146 feet higher 

 than High-street, receives on an average of both periods 

 more than three times the quantity. And this particular 

 fact is in harmony with the returns generally, showing that 

 elevation alone towards 2,000 feet does not determine the 

 amount of rain that shall fall into a rain-gauge. 



Speaking in more general language, it may be said that 

 the largest quantities of rain fall from warm and moist 

 atmospheres, as such atmospheres contain the largest 

 quantities of aqueous vapour ; and the rain is formed by the 

 condensation of a part of the vapour, at a height dependent 

 on the elevation that is attained by the atmospheric mass 

 when forced to ascend, and the difference between the 

 temperature and the dew-point in that mass. When the 

 dew-point is near the temperature at the surface, the largest 

 quantity of rain will be formed at a moderate height. When 

 the dew-point is more below the temperature, the largest 

 quantity will be produced at a greater elevation; and 

 when there is a great difference, or, in other words, when 

 the air below is dry, should any rain be formed it will 

 be at a great height, the particular locality in which the 

 largest quantity of rain falls, being always more or less de- 

 termined by the shape of the slopes of the land up which 

 the air ascends. If the rise of the land is great and abrupt, 

 approaching a vertical cliff, the larger part of the rain might 

 possibly fall on the low ground in front of the cliff, the 



