RATE OF DENUDATION 227 



therefore hope to be eventually in possession of trust- 

 worthy statistics on this interesting subject. 1 



The Denudation of the Surface of the Land by the 

 combined agency of the subaerial forces of decay is a 

 problem which has been much studied, but in regard 

 to whose varying rates of advance not much has been 

 definitely ascertained. The meteorological conditions 

 under which it takes place differ materially according 

 to latitude and climate, and doubtless its progress is 

 equally variable. An obvious and useful source of 

 information in regard to atmospheric denudation is to 

 be found in the decay of the material of buildings of 

 which the time of erection is known, and in dated 

 tombstones. Twenty years ago I called attention to 

 the rate at which marble gives way in such a moist 

 climate as ours, and cited the effects of subaerial waste 

 as these can be measured on the monuments of our 

 graveyards and cemeteries. 2 I would urge upon town- 

 geologists, and those in the country who have no 

 opportunities of venturing far afield, that they may 

 do good service by careful scrutiny of ancient buildings 

 and monuments. In the churchyards they will find 

 much to occupy and interest them, not, however, like 



1 The first Report of this Committee was submitted to the South- 

 port meeting of the Association in 1903. But the question is one 

 of such importance in view of the rapidity with which some parts 

 of our coast are in course of demolition that it deserves to be taken 

 up as a national investigation. The country at large should con- 

 tribute to the expense of applying the best means for arresting the 

 waste of its shores. At present the contest has to be carried on 

 by the riparian proprietors, who are often quite unable adequately to 

 cope with it. October, 1904. 



2 Proc. Roy. Soc. Edm., vol. x. (1879-80) p. 518. 



