162 THE FLOOD IN THE GABE TALLET. 



must not be forgotten that rain fell in almost unprecedented 

 torrents, that it poured in rivers off meadows that usually 

 absorb all that falls upon ihem, and, lastly, that atmospheric 

 evaporation must, under such conditions, have been inconsiderable. 

 After carefully considering the whole of the authentic information 

 that I have been able to collect, and making every allowance for 

 the eilect of absorption and evaporation, I think it is reasonable 

 to suppose that at least 25 per cent., or one-quarter part of the 

 entire weight of rain that fell within the defined area, would reach 

 the rivers within the first six hours subsequent to the stonn. 



I will now proceed to summarize my conclusions. I have 

 estimated that the watersheds supplying drainage to the Bulborne 

 and Gade comprise an area of about 34 square miles. It has been 

 shown that 2^ inches of rain fell during the continuance of the 

 storm, and it follows, as a matter of course, that somewhere about 

 5,500,000 tons of water must have fallen during the night, within 

 the area of drainage. If I am correct in supposing that 25 per 

 cent, of this enormous downpour found its way pretty directly into 

 the streams, it is evident that an extra demand, equivalent to the 

 accommodation of 1,375,000 tons, was made on their capacity. I 

 shall assume that the whole of this extra quantity of water passed 

 Ilunton Bridge during the ensuing day, and when it is remembered 

 that the average flow of water at that place does not exceed 

 192,000 tons in 24 hours, an easy calculation establishes the 

 i-emarkable fact, that on the 3rd of August an extra volume of 

 water, exceeding seven times the amount of the usual current, 

 forced its way along the valley of the Gade. 



I hope that these figures may sufficiently account for the occur- 

 rence of the unprecedented flood which I have now attempted to 

 describe. 



