268 Mr. A. B. Northcote on the Water of 



stinctly. It appears to have been a dry year ; and on the four 

 days on which the water was collected, the river was either quite 

 or almost at low water. In September, November, and March 

 its concentration corresponded with this state of things ; but on 

 the 1st of June, with a height of 10 feet, its dissolved matter 

 had fallen to nearly the amount which it contained after the 

 flood of February 1 867, when the river had reached a height of 

 more than seventeen feet. The explanation of this appears to 

 be that, as from the observations at Shiffnal and Bromsgrove 

 drought prevailed in those places, we may assume that over that 

 district in general the same condition existed ; whilst, on the 

 other hand, from rain occurring towards the end of May at Os- 

 westry, we may suppose that a purer and perhaps a Welsh water 

 suddenly filled the river, and reached Worcester comparatively 

 uncontaminated by the soluble or insoluble constituents of the 

 New Red Sandstone. The conditions of the rainfall of 1866-67 

 were very different, and by no means so well calculated to place 

 its influence in a striking light ; still the details are explanatory 

 of the state in which the river was on the days on which the 

 specimens were taken. After a period of comparatively dry 

 weather, rain probably fell, during the few days which preceded 

 the 12th of April, over nearly the whole course of the Severn and 

 its tributaries. This corresponds with the considerable height of 

 13 feet 6 inches which the river attained at Worcester, and it 

 also explains how the river brought down at this time the largest 

 amount of sediment which I have found it to deposit ; for it is 

 a matter of observation that the greatest quantity of suspended 

 matter* is carried into a river during the first days of rain. The 

 wide distribution of the rainfall, moreover, accounts for the con- 

 siderable quantity of dissolved matter which this water contained; 

 in this respect it affords a very useful contrast to the water of 

 June 1858, and shows the great difference of result between a 

 rainfall high up the river, and one which also extends over the 

 district of the New Red Sandstone. The water of July had evi- 

 dently been concentrated by evaporation during the prevailing 

 drought, and it needs no further remark; but with regard 

 to the water of October some few observations are required. 

 It must be remembered that the river was very high at Wor- 

 cester during the early part of the month, and had fallen 

 gradually up to the time at which the water was collected : 

 the reports of most of the observers along its course accord 

 with this, and state that more rain had fallen earlier in Oc- 

 tober than during the day or two which could influence the 

 water of the 30th. This, therefore, clearly accounts for the small 

 quantity of sediment which this water yielded, for the first rain 

 * Bischof (Cav. Soc), vol. i. p. 120. 



