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April 27. — William Pyle Taunton, Esq., of Stoke Bishop, near 

 Bristol, was elected a Fellow of this Society. 



A paper was read, entitled, " On some effects of the atmosphere 

 in wasting the surfaces of buildings and rocks:" by John Phillips, 

 Esq. F.G.S., &c. 



The remarks in this paper are restricted to the initial or prepa- 

 ratory processes by which earthy materials are provided for rivers and 

 the sea to transport and deposit in new situations. These processes 

 are considered by the author under several heads, according to their 

 chemical and mechanical relations ; but he observes that it is not 

 always possible to distinguish accurately the effects of these several 

 causes, which indeed are commonly concerned in the same ope- 

 ration. 



The author, after stating some of the changes produced upon va- 

 rious rocks and buildings by the chemical agency of the gaseous ele- 

 ments of the atmosphere, illustrates the almost entire immunity from 

 such alterations enjoyed by substances buried in the dry earth, by the 

 remarkable perfection of sculpture, colour, and gilding, of the statues 

 formerly placed in St. Mary's Abbey at York, which were recently 

 discovered in digging the foundation of the Yorkshire Museum. 



The more rapid waste of those parts of a building which are shaded 

 by a projecting ledge, is compared with analogous effects upon de- 

 tached blocks of stone (like the Buckstone near Monmouth), which by 

 a further continuation of the process might be transformed into rock- 

 ing-stones, as at Brimham Crags in Yorkshire. The rapid waste oc- 

 casioned by fluctuations of heat and moisture is next examined; and 

 it is shown that the south and west fronts of buildings suffer most by 

 these variations ; that when the composition of the stone is unequal, 

 the waste of its surface corresponds in general to the nature and ar- 

 rangement of the particles ; but that also there are cases when the 

 atmospheric influences cause an exfoliation of the surface, without 

 reference to the internal arrangement of the particles. Thus, de- 

 squamation is observed to happen parallel to the ornamented sur- 

 face of the sandstone balusters of a bridge at Durham, to the rounded 

 face of the " flagstone" employed for curbstones at York, to the em- 

 bossed tooling of the "molasse" used in the walls of Zurich, and to 

 the west front of the magnesian limestone of a church in Yorkshire. 



The power of frost in connection with other agents is then noticed 

 as very important in producing the fall of mountain precipices ; and 

 the author concludes his paper with a description of some remarkable 

 excavating effects of rain on the surfaces of ancient monumental 

 stones and bare limestone rocks. He endeavours " to show, that 

 within the historic sera hard and durable stones have been greatly 

 furrowed by the rain, and that in more ancient periods the precipita- 

 tions from above have carved themselves channels of various kinds, 

 and sometimes occasioned real though miniature valleys of great 

 length and continuity." 



The first example of these rain channels is taken from the druidi- 

 cal stones of Boroughbridge, composed of millstone grit, called the 

 Devil's Arrows; and it is shown that the rain beating upon these vene- 



