i Proceedings. 
Park Hill-rise and the Waterworks tower. After referring to 
the unavoidable mistake that had been made owing to the 
absence of sections when this neighbourhood was first mapped 
by the Survey, and to a slight inaccuracy that had been con- 
sequently found to exist in the map that accompanies Professor 
Morris’s lecture on the geology of Croydon, Mr. Chisholm said 
he should take advantage of this error on the part of the Survey, 
to point out the utility that would attach to a record of local 
sections as that which had that evening been brought forward, 
and suggested that the examination and recording of these 
sections should be done systematically by a sub-committee of 
this club. Even one isolated section might not be without 
» some use, but the combined record of a great many sections 
would be of far greater and more practical importance. A 
great part of the neighbourhood of Croydon was covered by a 
superficial deposit of gravel which filled up the hollows, and 
effectually concealed every indication of the stratification 
beneath. It was only when some opening in the gravel 
chanced to be seen and the dip of the underlying strata noted, 
that a calculation could be made of their probable direction 
underneath, and the spot at which they terminated. Thus, when 
our acquaintance with the solid geology, as it is called; in its 
minor ramifications, was founded on one or two only of such sec- 
tions, it was little more than guess work, and it would be neces- 
sary to multiply observation upon observation to attain anything 
like exact knowledge. Ina growing neighbourhood like this, 
constant opportunities were presenting themselves for a better 
acquaintance with the ground beneath us ; openings were being 
made on every side, and these were so numerous, and in so 
many different localities, that it required the co-operation of 
many observers to take note of any large proportion of them. 
They could not expect a member of the Survey to be always 
on the spot to take note of sections ; such work must be left to 
residents. If it were undertaken we. should have the data 
ready to our hand to assist us in carrying out more thoroughly 
our drainage operations, and thus in approaching a more 
perfect sanitary condition, and a consequently higher standard 
of health. 
In the discussion which ensued, Mr. F. Warren and Mr. 
H. M. Klaassen took part. 
Mr. TurNER said he had been invited last spring by Mr. 
Chisholm to inspect the section, under circumstances less 
favourable than he could have desired. The conflicting appearance 
of the section puzzled him, and he had some difficulty in 
making out the relation of the different beds to each other, and 
therefore the opinion he was about to offer might not be worth 
