Ixxiv. Proceedings. 



series were well seen in one or two excavations recently made 

 in digging foundations for new houses. 



Near the southern end of Ashburton Road the party left 

 the Addiscombe Road, and, by the kind permission of the occu- 

 pier of the land, H. Johnson, Esq., examined two very 

 remarkable springs in the side of the hill, on the south side of 

 the road, one at a point about 30 feet, and the other about 40 feet 

 above the level of the road. The former of these, which is by 

 far the larger of the two, is about 250 feet above the sea level. 

 It has hol'owed out for itself a considerable basin in the hill 

 side, which has probably been increased artificially; and 

 the stream, which flows from this, has cut out a considerable 

 valley down which it passes. These features were here pointed 

 out by Mr. Flower, who also explained the boundaries and 

 general structure of the hill, and of the Oldhaven, and Wool- 

 wich, and Reading beds, of which it is composed. He also 

 explained that there were numerous similar springs along the 

 northern side of this hill, and that these form the sources of 

 the rivers Wandle and Ravensbourne. The probable explana- 

 of these springs is that they arise at points where clay beds, 

 sloping to the north, come to the surface of the ground on 

 the side of the hill, and then discharge the water which is 

 received and absorbed by the large masses of pebble beds 

 which are over the clay. 



Returning to the road, another small valley, cut by similar 

 springs, was seen close to Lady Ashburton's farm ; and the 

 party then proceeded to Shirley House. Near the lodge gate the 

 water-shed ridge (here broad and flat) which divides the basins 

 of the rivers Wandle and Ravensbourne was reached, and 

 its course through the grounds of Shirley House, and along 

 the edge of the fields on the west side of the Stroud Green 

 Road was pointed out and described by Mr. Flower, who also 

 pointed out a spot, on the water-shed ridge, in a ditch, about 40 

 yards from the Stroud Green Road, where, in winter, a spring 

 rises, from which the water flows eastward into the Ravens- 

 bourne, and westward into the Wandle. 



In the grounds of Shirley House, which were courteously 

 thrown open to the party by F. Banbury, Esq., another fine 

 spring, the water from which was received into a large brick 

 tank, was inspected and described; and from this the party pro- 

 ceeded to the small lake, situated in a valley, which is cut 

 through the pebble beds and Thanet sands down to the chalk, 

 the lake itself appearing to rest, for the most part, if not 

 entirely, on the sand, and to be fed by springs from the pebble 

 beds. The overflow from this lake passes into the Ravens- 

 bourne, the valle}' in which it is situated, being the most 



