Proceedings, xcvii 



lowest level, attaining a maximum height between February and 

 June. In the lower ground, nearer Croydon, the epochs of 

 minimum and of maximum water-level are respectively about a 

 month later. This may be seen by comparing the observations 

 at Slynes Oaks with those at Addington Village, although the 

 comparison is somewhat vitiated from the two stations not being 

 in the same drainage area. I am informed by Mr. Latham that 

 the rate of propagation, of what may be termed a wave of water 

 downwards from the hills, is less speedy in some valleys than in 

 others, and that it is retarded in the valley leading from Farley 

 towards Addington. This is probably to be attributed to the 

 greater or less obstruction to the flow of the water through strata 

 of varying density, or to the chalk being more or less fissured, and 

 to the comparative length and steepness of the gradient of the 

 impermeable floor of the individual valley. There are, however, 

 many subsidiary points bearing upon the question which need 

 investigation. To conclude my remarks on this subject, the 

 variation in the level of the water is much greater in the deep 

 wells among the hills than in the shallow wells sunk in the lower 

 ground. It amounted to 95 ft. at Crewe's Farm and 66 ft. at 

 Slynes Oaks, as compared with 27 ft. at Addington Village and 

 17 ft. at Sparrows Den, West Wickham. But the twenty wells 

 observed by the Corporation of Croydon are not altogether best 

 calculated to exhibit these phenomena in the clearest light, 

 being for the most part situated in a band from east to west 

 transversely to the flow of the water. A detailed statement of 

 the well-measurements is given in the Transactions (Trans., 

 Art. 74). 



I am indebted to Mr. Mennell and to Mr. McEean for the 

 following Eeports relating to the Botanical and Photographic 

 Sections respectively. It will be noticed that the Botanical 

 Sub- Committee, for weighty reasons, has substituted the county 

 of Surrey as its special field of operations for the natural district 

 adopted by the other sections of the Club. 



Report of the Botanical Sub-Committee, January, 1889. 



The Botanical Sub-Committee has now thoroughly taken in hand 

 the formation of the Club Herbarium, for which an excellent cabinet 

 has been purchased and placed in the Committee-room. 



The collection will be strictly limited to plants gathered in the 

 county of Surrey, but will not be restricted to the plants of the special 

 district to which it was at one time proposed to limit the operations 

 of the Club. 



The late Mr. Flower very carefully mapped out such a district for 

 the Club, based upon the Hmits of the river-basins, and these doubtless 

 form the most truly natural areas for the study of the distribution of 

 the fauna and flora. In the district thus mapped out certain portions 

 of the county of Kent forming part of the drainage area of the 



