JF. W. Watts—British Geological Photographs. 33 



inconceivable that the influence of the collection has had somethino- 

 to do with bringing about this result. But much of the work ol' 

 amateurs is not at present available for this purpose, althouo-h it is 

 superior to all but the very best professional work in the fects it 

 delineates, albeit usually inferior in technical execution As the 

 committee's work progresses it should be possible to indicate where 

 pictures of the most typical examples of rock-structure, features of 

 landscape, phenomena of denudation and deposit, glacial action etc 

 are to be obtained, even if it should still not be possible to reproduce 

 them by process in a collected form. 



The element of time enters into the interest of this collection in at 

 least two ways. Firstly, we may sometimes register the effects pro- 

 duced by geological causes during the lapse of years. The advance 

 ot the sea at Keculvers would impress us even more than it does in 

 the two drawings copied in Lyell's "Principles," if he had been able 

 to give two photographs taken from the same spot instead In 

 lintam we cannot register such physiographic changes as the 

 destruction and rebuilding of volcanic cones, the uprise and down- 

 la 11 of the sea, the effects of great earthquakes, the advance and 

 re reat of glaciers, and the like ; but we have landslips, floods the 

 tilling up of lakes and estuaries, the advance of sand-dunes and 

 erosion by streams, seas, waterfalls, and wind. 



One of Miss Andrews' photographs shows an unexpected instance 

 ot this kind : a pump erected in 1824, to get the water out of a 

 stone quarry near the coast in County Down, is now to be seen 

 :, ^f ^ °"t/t «ef^/ and one by another hand shows that the shaft at 

 the back of an old cave by which smugglers used to pass their ill- 

 gotten goods mland is now at the mouth of the cave, and all but cut 

 away by the general wear and tear of the coast, while the cave 

 Itself has been worked back. Others show in minute detail the 

 outline of the coast at Filey, Flamborough, Sunderland, etc., so that 

 It will be possible to see the progress of future denudation by com- 

 parison with them. ^ 

 _ On the other hand, the duration of exposures of geological features 

 IS often only temporary : railway cuttings become grassed over 

 quarries abandoned and closed, trenches and subterranean works 

 Ulled up and built over, rock exposures soiled over and planted 

 or even submerged, boulders are broken up and disappear, sea cliffs 

 are worn back or hidden by landslips. All these things might be 

 preserved on paper, so that it is possible to check conclusions 

 founded on them by reference to photographs even when thev are 

 no longer open to examination. The Cambridge Greensand is 

 becoming an unseen stratum, the Crags are gradually disappearing, 

 gravel beds and road-metal quarries are being worked away, stonj^ 

 formerly much worked are being abandoned; records in the form of 

 pnotographs as well as descriptions ought to be kept Sir II T 

 Woods photographs of the excavations in the Beer-stone, I believe* 

 show features no longer to be seen; and the photographs of the 

 stages of working of the great quarries at Bardon and Mount Sorrel 

 preserved in the collection will be of interest to those who read the 



DECADE IV. YOL. IV.— NO. I. q 



