CHAPTER VII. 



BY RIVER AND POOL. 



BROADLY speaking, the northern shires are 

 remarkably well- watered ; not only by a net- 

 work of rivers, but by an almost endless succession 

 of pools and lakes, canals and dams, the latter to 

 some extent being due to the necessities of the vast 

 and busy centres of manufacture and commerce. 

 Bird-life in great variety and of exceptional interest 

 is to be found upon these rivers and pools and along 

 their banks and margins, and again presenting us 

 with not a little room for comparison with that 

 frequenting similar localities in more southern coun- 

 ties. Here ao-ain we miss some birds that are 

 familiar farther south ; we find others that are rarer, 

 or less known there. Unfortunately too many of 

 these northern waters are polluted, especially in their 

 lower reaches and in the immediate neighbourhood 

 of towns, by drainage and factory refuse of various 

 kinds. Rivers that run in their higher reaches over 

 moss-grown stones and sandy beds, clear as crystal, 

 and fringed on either bank with brushwood and 

 timber, become little more than open sewers as they 

 pass the big centres of manufacturing life. The 



