the River Severn at Worcester. 



267 



Rainfall about some of the sources of the Severn and of its 

 tributaries. 



Place 



Llanidloes. 



Oswestry. 



Shrews- 

 bury. 



Shiffnal. 



Wolver- 

 hampton. 



Broms- 

 grove. 



Above sea-level 



750 feet. 



270 feet. 



200 feet. 



450 feet. 



520 feet. 



273 feet. 



1866. 















April 7. 



•50 







•30 





•010 



8. 













•005 



9. 







•03 



•20 





•065 



10. 



•40 



•55 





•50 



•07 



060 



11. 





... 





•20 



•02 



•070 



Julv 18. 















19. 





... 



... 



... 







20. 







... 



... 







21. 















22. 





... 











October 25. 





•64 



•25 



•30 



108 



•125 



26. 



•70 







•40 





•040 



27. 



... 





•03 



•17 



02 



•080 



28. 



... 





•10 





•15 





29. 







... 



•30 





•150 



1867. 















Februarv 9. 





... 



•01 



•17 





•080 



10. 







•27 



14 



•29 



•260 



11. 





... 



•14 









12. 















13. 





•85 











I have found that the observations of rainfall for many of the 

 places mentioned above do not go back so far as 1857-58, during 

 which year the first analyses were made ; but the observers at 

 Oswestry, Shiffnal, and Bromsgrove have kindly furnished me 

 with sufficient facts to show that at these places no rain fell for 

 several days before the waters were taken in September, Novem- 

 ber, and March, and in May the only rainfall was at Oswestry. 



A river must derive its water from two sources, one immedi- 

 ately, the other intermediately dependent upon rainfall. To the 

 latter belong all the phenomena of springs, which frequently 

 afford a very equable supply of water, and augment the bulk of 

 a river in no inconsiderable degree ; they are, however, connected 

 with a rainfall of too uncertain remoteness in time, and perhaps 

 in place, to admit of comparison with any given condition of the 

 river. The immediate rainfall, on the other hand, produces not 

 only a marked effect upon the height of the river at a given 

 place, but also on the nature and amount of its constituents, 

 dependent upon the geological character of the country in which 

 the rain occurs. The analyses of 1857-58 exhibit this most di- 



T2 



