NATURAL HISTORY. 



311 



Elvers. 



In an agricultural survey' of Mid- 

 dlesex, the rivers, which contribute 

 so much to the fertility of the land, 

 ought not to be omitted. Being 

 immediately connected with the 

 New River, which takes its course 

 for nearly a mile through ray own 

 estate, I shall minute down a few , 

 particulars worthy of notice. The 

 New River rises in a rich valley, 

 about half way between Hertford 

 and Ware. The water at the foun- 

 tain head, which is remarkably clear 

 and pure, collects in a circular ba- 

 son ; it then takes a course through 

 Amwell and Hoddcsdon, nearly 

 parallel with the London road ; at 

 Cheslmnt, Theobalds, and Enfield, 

 it winds through several parks and 

 gardens, not only supplying tiie in- 

 habitants ©f th jse districts with wa- 

 ter, but enriching the country with 

 the fertility and beauty of its stream; 

 at Enfield, after, passing through 

 White Webb's farm, it just touches 

 on Enfield-chase, and returns im- 

 mediately through the same farm, 

 in a direction nearly parallel to its 

 former course, and thus encloses 

 completely a large tract of rich 

 meadow-land, which requires no 

 other fence. The mode of conduct- 

 ing streams across vallies was but 

 little understood when this river 

 was first formed, otherwise, so cir- 

 cuitous a course, to preserve the 

 level, would have been unnecessary. 

 On the chase, in its turn, it crosses 

 a narrow vale, x^hich after heavy 

 rains it frequently Hooded. The 

 water being obstructed in its course 

 by the banks of the river, would 

 certainly have overflov/ed and da- 

 maged the river water, with th'e 

 impurities of a land flood, hiid not 

 this mischieCbeen prevented, by an 



arch ofbrick-work, which is thrown 

 across the liver, by means of which 

 the waters collected in the valley, 

 after heavy rains, pass over the 

 stream without injuring it. In a 

 wet season, so large a sheet of wa- 

 ter, rushing over the New River, 

 with great noise and mnpetuosity,. 

 forms a very grand cascade. 



Between Enfield and London, 

 the New River winds in so singular 

 a manner, that in the course of ten 

 miles you pass it as many times. 



The weeds at the bottom of the 

 river are repeatedly cut, and the 

 mud cleared away, in order to pre- 

 serve the channel free and open for 

 the course of the water. For tl>e 

 care of the banks a walksraan is 

 appointed to every two miles. On 

 trying the mud of the New River, 

 in the neighbourhood of Enticld, I 

 found it strongly calcareous ; a con- 

 siderable effervescence ensuing on 

 being mixed with acids. This is 

 owing to the admixture of s4)ells 

 and fresh water snails, which, con- 

 tinually subsiding, give a marly na- 

 ture to the earth at the bottom of 

 the stream. If we consider that it 

 is now one hundred and eighty 

 years since the river was completed, 

 the quantity of calcareous matter 

 thus accumulated must be consider- 

 able. The chalk which abounds 

 in the neighbourhood of Hertford 

 and Ware, where the river rises, 

 may furnish an additional supply of 

 the calcareous eartli. On using this 

 river mud, as a manure on meadow 

 land, I have found tbe pasture 

 sweetened by the great increase of 

 the white clover. Thejloiefcscui' 

 grass prevails much on the banks qf 

 the New River, owing probablv to 

 llie calcareous mudsciape ; v.pjj-o'cp. 

 the bottom, and with which ' Uie 

 banks arc continually rclJ-lirec!. 

 X 4 This 



