14 KEPOBT AND OBSERVATIONS ON 



Li the upper part of the valley the tributary streama, 

 falling frora 1000 to 1200 feet in a few miles, join the main 

 stream in the valley of Longdendale, nearly at right angles, 

 thus breaking the surface of the country into various cross 

 valleys and deep ravines. The summit of this district is 

 Holme Moss, nearly 2000 feet above the sea. It is the 

 highest eminence in the whole chain, though it rises but 



A little consideration will greatly lessen our surprise at the enormous 

 quantity of water deposited in the hilly districts of Cumberland and West- 

 moreland, and at the consequent unequal distribution of the rain in the 

 climate of Great Britain. To those unacquainted with these localities it 

 mfay be briefly stated, that the Lake District valleys radiate from a series 

 of mountains of slate and primitive rock, having the Gabel, 2928 feet 

 in height, as a nucleus or central point ; and in the immediate vicinity of 

 which are Sea Fell and Pillar, of the respective elevations of 3166 and 

 2893 feet, and Great End, Bowfell, and Glaramara, not much inferior in 

 altitude. These mountains are distant only about thirteen or fifteen miles 

 in a direct line from the Irish Channel, and, as no hills intervene, they are 

 consequently fully exposed to our wet and prevailing winds, which are the 

 south-west. The warm south-westerly current arrives at the coast 

 loaded with moisture, obtained in its transit across the Atlantic : — Now, 

 our experiments justify us in concluding, that this current has its maximum 

 density at about 2000 feet above the sea level ; hence, it will travel on- 

 ward until it is obstructed by land of sufficient elevation to precipitate its 

 vapour; and, rttaining a portion of the velocity of the lower parallel of 

 latitude whence it was originally set in motion, it rapidly traverses the 

 short space of level country, and with little diminution of its weight or 

 volume ; but, on reaching the mountains, it meets with a temperatmre 

 many degrees lower than the point at which it can continue in a state of 

 vapour ; — sudden condensation consequently ensues, in the form of vast 

 torrents of rain, which in some instances' must descend almost in a con- 

 tinuons sheet, as when nine or ten inches are precipitated in forty-eight 

 hours. When we reflect that a warm moist current, perhaps only 3° or 4o 

 above the point of saturation, in coming in contact with the mountain 

 ridge, probably meets with a stratum of air 10° or 15° lower than its own 

 inherent temperature, we shall cease to marvel that such quantities as four, 

 five, or even six inches of water should be deposited in these localities in 

 the course of a few hours. The mountains are, in fact, huge natural con- 

 densers, destined to force from the atmosphere the mighty volumes of 

 water requisite for the supply of our lakes and rivers." 



