64 SALMONIA. 



part of the Teme river in Herefordshire, 

 where it receives the Clun: they are now 

 seldom or rarely seen. And most of the 

 rivers of that part of England, as well as of 

 the west, with the exception of those that 

 rise in the still uncultivated parts of Dart- 

 moor and Exmoor, are after rain rapid and 

 unfordable torrents, and in dry summers 

 little more than scanty rills. And Exmoor 

 and Dartmoor, almost the only great remains 

 of those moist, spongy or peaty soils which 

 once covered the greatest part of the high 

 lands of England, are becoming cultivated, 

 and their sources will gradually gain the 

 same character as those of our midland and 

 highly improved counties. I cannot give 

 you an idea of the effects of peat mosses and 

 grassy marshes on the water thrown down 

 from the atmosphere, better, than by com- 

 paring their effects to those of roofs of 

 houses of thatched straw, as contrasted with 

 roofs of slate, on a shower of rain. The slate 

 begins to drop immediately, and sends down 

 what it receives in a rapid torrent, and is dry 

 soon after the shower is over. The roof of 



