•274^ 



DRAINING 



Sect. XI. 3. i. 



.water In rainy feafons Is loaded with difFulcd as well as with dlfTolved 

 materials From the neighbouring country. 



Both thefe therefore are of great fervice In flooding: meadow- lands. 



d. perhaps aim oft all oth 



ds 



B 



thofe 



gs, which 



pafs 



lyth 



:l 



filiceous fandflone, as thofe at Lichfield In StafFordfti 



have no calcareous earth difTolved In them, as I have found by expe- 

 rirnent ; and the water of moft rivers, when they are not fwelled by 



rain, 

 ready 



alfo too pure for th 

 their courfe the ca' 



purpoll 



e 



as they have depofited al- 

 th, which might abound m 



the fprings, which feed them ; as I have obferved by experiments on 

 the water of the Derwent at Derby, which though it runs for manv 



r 



miles about Matlock through a bed of llmeftone, yet when clear of 

 mud from rains, it contains no calcareous earth, as it palles 



Derby", though the fprings In the vicinity are replete with it. Nei- 

 ther of thefe fources of water can therefore do much fervice for this 

 fecond defign of depofiting limeftone, or 



^ , or mud 



The third advantage of flooding lands in 



this 



mate is for th 



purpofe of defending them from the cold of the winter or vernal 



month 



For this advantage the water from flron 



o 



fprings^ which 



are 



always at 48 degrees of Farenheit in this country, is preferable 

 to river water, where it can be had In fufficlent quantity; fince the 

 water of rivers Is of the fame degree of cold as the atmofphere, till 

 the thermometer finks to 32. But both of them, when they form a 



I 



Hieet of th 



as 



they 



meadow, defend the roots of th 



t> 



fs from feverer degrees of cold 



& 



hich are th 



prefer ved, and 



thofe of fome graffes are believed even to vegetate beneath the ice, 

 the rein-deer mofs in Siberia vegetates beneath the fnow in a deo- 



of h 



about 40, which is the medium between that of th 



der 



furface of the thawing fnow, which is 32 ; and that of the common 



heat of th 



parts oF th 



r 



th, which Is 48; and th 



th 



i:ops of grafs in this cold climate may be wonderfully forwarded ; fo 



as 



I 



