260 REPORT OF MEETINGS FOR 1905 



position forming the main bulk of the hill. The third intrusive 

 mass is of a similar composition to that of the highest lava 

 of the Queen's Park, and is essentially an andesite. This 

 rock forms a series of apparently discontinuous wedges, which 

 are intruded into the Ballagan Beds on the East side of 

 Hunter's Bog, and compose the hills called the Dasses. 

 With reference to the shaping of the minor details of the 

 surface of Arthur's Seat, three factors must be 

 Details of borne in mind. First, the result of prolonged 

 Surface. exposure of rocks, of very diverse powers of 



resistance, to atmospheric waste ; second, the 

 influence of streams in excavating their own channels without 

 having their courses affected by the minor changes otherwise 

 occasioned ; and third, the effect of prolonged glaciation, which 

 not only very materially modified any pre-existing features 

 it might encounter, but left impressions peculiarly its own, 

 as may be noted in the numerous small rock basins which 

 have been hollowed out in the lavas of Whinny Hill, as, 

 for example, in Samson's Grave. 



At various points on the route, which lay by St. Anthony's 



Chapel, Whinny Hill, Dunsappie, Duddingston, 



Queen's and Samson's Ribs to St. Leonard's Hill, oppor- 



Drive. tunity was taken to illustrate the theory of 



rock formation by the testimony of the rocks 



themselves, and to afford information regarding the many 



historic sites and country-seats in which Midlothian abounds, 



so that the excursion, albeit not without fatigue, proved 



intensely interesting and profitable. As commonly happens, 



the time available was insufficient to allow of everything 



being done with deliberation, so that on reaching the Park 



gate, the members learned that a rush would have to be 



made to gain the place of entertainment by the hour 



appointed. 



For the convenience of those leaving town by rail, the 



dinner was arranged for in the Imperial Hotel, 



Club Waverley Bridge, at 5 o'clock, when a goodly 



Dinner. representation of members sat down to an 



excellent repast, presided over by Mr Wm. B. 



Boyd, who had been one of the party throughout the entire 



day. On the motion of Captain Norman, E.N., Mr Goodchild, 



