140 JOHN EVANS — THE HEETFOEDSHTBE BOIIENE. 



usual. There had only been, during the six months ending the 

 3 1st March, about six inches, and in April another half -inch of 

 rain, which passed down through three feet of soil. That is rather 

 a small amount of rain to enable the Bourne to flow ; but when we 

 look at the amount of rainfall there has been for some years, I 

 think the reservoir has not been at so low a level when the 

 infiltration commenced, as on some other occasions, and although 

 generally speaking the flow of the Bourne is connected with the 

 amount of infiltration of water during the six months or so 

 preceding, yet we must take into account the state of the springs 

 and subterranean reservoir during the previous years. 



I will not go into the question of the infiltration into the 

 subterranean reservoir, as I hope to lay some observations on this 

 subject before the Society in a printed form, having embodied them 

 in a communication to the Society of Ciyil Engineers.* 



N"oTE. — January 31st, 1877. The Bourne is again running, 

 having commenced to flow on the evening of the 6th, or the 

 morning of the 7th. I was at Bourne End on the afternoon of 

 the 6th, and the bed of the stream, where it passes under the road, 

 was free from water. On the 7th, Mr. Littleboy visited the spot, 

 and found the stream running. I have since seen the Bourne 

 flowing in considerable volume, and have ascertained that the 

 position of its present source is as nearly as possible the same as 

 it was in Eebruary, 1873. The Bourne in the Caterham Yalley, 

 near Croydon, is also flowing in a powerful stream. — J. E. 



* Proc. Inst. C.E. vol. xlv. Feb. 29, 1876. 



