INTRODUCTION. XXIU 



rine Coleman. It ran west through Lorahard Street as far as St. Mary- 

 Woo hioth, then turned south and united with the Wall Brook. From 

 the stream overflowing and rendering the road swampy, ' the way was 

 called Fenchurch Street near the church ' (Noorthouk's History of 

 London, 1782). 



Walhrook entered the city between Bishopsgate and Moorgate 

 through the wall, whence its name (Sto2v, Thom's ed. p. 45). After 

 many turnings it flowed through the street now called Walbrook to 

 the river at Dowgate. Formerh^, says Stow, ' a fair brook of sweet 

 water,' but in 1598 it had been some time arched over, and ' the trace 

 thereof hardly known to the common people.' 



These old watercourses of the metropolitan district have long since 

 ceased to possess any place among the physical features of the county, 

 and have been merged into the general sewer system. It is, however, 

 desirable to trace out their former history, as their names occur in the 

 writings of the older botanists, many of whose collecting grounds, as 

 well as the streams that drained them, have been absorbed by the 

 growth of London. 



The iea rises in the Chiltern Hills in Bedfordshire, flows south-east 

 through Herts, the eastern two-thirds of which is drained by it and 

 its tributaries ; then flows south, separating Essex from Herts and 

 Middlesex (which it first touches at its north-east corner a little 

 below Waltham Cross), to fall into the Thames at Bow Creek, a little 

 east of Blackwall. 



The Lea receives several brooks from the east part of the county, 

 the largest being Salmon's Brook, rising by surface drainage from the 

 country formerly called Enfield Chase, east of the road from Baruefc 

 to Hatfield. Another small tributary drains what was formerly 

 Finchley Common, and the country about Southgate and Colney 

 Hatch (and East Barnet in Herts). The main stream of the Lea 

 itself has been rendered navigable for about eight miles from the 

 Thames. Beyond this a canal runs parallel to it through Tottenham, 

 Edmonton, and Enfield Marshes to Waltham. The Lea is connected 

 with the Paddington Canal by a cut called Sir G. Duckctfs Reser- 

 voir, and with the Thames at Limehouse by another called the 

 Limehouse Cut. 



In addition to the natural rivers and streame of Middlesex there 

 are many artificial watercourses which, especially in so small a county, 

 deserve description amongst the other physical features. As the 

 habitats and means of distribution of water-plants, their names are 

 often mentioned, and in this respect they are probably of equal 



