K. B. CKOFT — OX THE BIVEE LEA BELOW nERTFOED. 247 



of its course as the IMnr DylvC, branches off from its loft bank. 

 Between the towing-path and meadows on the same bank is a 

 maguiticent hawthorn hedge, quite five-and-twcnty feet high, de- 

 scribed as "a marvel of radiant May-blossom in spring." At 

 Ponder' s End the navigation, after cutting off an angle of Essex, 

 again crosses the old channel and is continued towards London, 

 while the pleasant old river, reinforced by the truant waters of 

 the Mar Dyke, washes the foot of the Essex hills near Chingford, 

 gives up much of its water to supply the reservoirs of the East 

 London Water Works Company, and rejoins the navigation below 

 Tottenham. 



After this the river can hardly be considered interesting. The 

 navigable cut leaves the old river at Lea Eridge, and rejoins it 

 again at Stratford. From here a canal connects it with the Regent's 

 Canal, and another with the Thames at Limehouse. The real 

 mouth of the river, called Bow Creek, is at Barking, and is still 

 used for purposes of navigation. Thz'ee streams flow into the river 

 from its right bank below Broxbourne, namely the Turkey-street 

 brook, the Salmon brook, and the Moselle. Erora the junction of 

 the Stort to Waltham the old river divides the counties of Essex and 

 Hertford, below this it divides the former county from Middlesex. 



Having now traced the River Lea from its various sources to its 

 junction with the Thames, it may not be amiss to glance briefly at 

 the physiography and geology of its basin, which may be described 

 as a triangle, its southern angle being at its junction with the 

 Thames, and its north-western and north-eastern angles being near 

 Houghton Regis in Bedfordshire, and Henham-on-the-Hill, in Essex, 

 respectively. The area of this basin is about 500 square miles or 

 320,000 statute acres; it is bounded on the north by the Chalk 

 range which divides the basins of the Thames and Great Ouse ; on 

 the west are the watersheds of the Colne, and other Thames 

 tributaries ; on the east that of the Roding, except for a short 

 distance in Essex, where the water-parting divides the country 

 di'ained by the St;ort from that drained by the Chelmer ; hence at 

 a spot not far from Henham-on-the-Hill the watersheds of three 

 important rivers, viz. the Thames, Great Ouse, and Blackwater, 

 meet. The Chalk, either bare or covered with drift, takes up the 

 portion of the basin north of an undulating line from Hertford to 

 Henham ; the London Clay, the remainder ; the Lower London 

 Tertiaries having but a narrow outcrop between them. The various 

 divisions of the drift cover by far the larger portion of the district, 

 the boulder-clay alone occurring over a large portion of it. The 

 gravel and sand beneath the boulder-clay crop out mostly along 

 the bottom and flanks of the valleys ; whilst the smaller tracts of 

 Post-glacial gravel, etc., in great part border the streams of their 

 alluvial flats; but there are also patches of "plateau gravel" that 

 seem to be of this age, and others of loam that clearly overlies the 

 boulder-clay. Although most of the streams we have been con- 

 sidering are bordered by a flat strip of alluvium, their newest 

 deposit, there are no large spreads of it, the greatest being where 



