550 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 13, 



of the influence of drifting sand in wearing away the surfaces of hard 

 granite rocks. 



A little to the northward of Land's-End Point is Whitsand Bay, 

 the shore of which is covered with pulverized shells mixed with 

 minute grains of quartz, forming together a sand of dazzling white- 

 ness. The hill which rises behind this bay is clothed with very short 

 herbage, springing from a thick stratum of similar sand ; and it is 

 partly intersected by a ravine or glen, increasing in width and depth 

 as it descends rapidly in a W.N.W. direction to the bay or beach ; 

 and a little stream runs through the middle of it. The steep sides 

 of the glen, instead of being covered with herbage, consist of fine 

 white shelly and quartzose sand, like that on the beach, and numerous 

 granite rocks appear above the sand, many of them rising only a few 

 inches out of it, with nearly plane surfaces, sloping with the sand. 

 Other masses of granite rise many feet above the sand ; but all the 

 rocks are worn, and more or less polished, on those surfaces which 

 are inclined in any degree towards the beach, whereas their opposite 

 sides, facing towards the head of the glen, whether sloping or vertical, 

 are neither polished nor worn. It is evident that the dry sand, driven 

 by the currents of wind rushing up through the glen, has produced 

 these effects ; and, moreover, owing to the directing influence of the 

 glen on the wind passing through it, all the granitic surfaces which 

 are more or less inclined towards the beach are striated or furrowed 

 parallel to the direction of the glen, — that is towards the W.N.W., 

 except where the direction of the latter is a little changed, and there 

 that of the furrow s is changed with it. 



When the wind blew with only a moderate force up through the 

 glen, the surface of the sand was observed to be set in quick motion 

 before it ; but the tendency of the sand to slide down the slopes into 

 the stream limited its further accumulation. 



The loose stones on the sand, however hard, have their edges 

 rounded ofi" by the drifting sand, just as if they had been long exposed 

 to the action of water in motion, whereas the stones and granite- 

 rocks at and near the head of the glen, and on other parts of the hill, 

 are not polished, furrowed, or rounded like those exposed to the 

 action of the drifting sand. 



8. Remarks on the Brown Coal of the North q/" Germany. By 

 Professor Beyrich. Communicated, with Observations, by 

 W. J. Hamilton, Esq., Pres. G.S. 



Having received from Professor Beyrich a letter, in which reference 

 is made to the Brown Coal of North Germany, and of which the 

 following communication is an extract, I think it right, for the pur- 

 pose therein mentioned, to lay it before the Society. 



*' A serious error has crept into your last paper respecting our 

 Brown Coal formations *, occasioned, as it appears, by a not suffi- 

 ciently clear statement in Plettner's Memoir on the Brown Coal of 

 * Anniversary Address, 1855, Quart. Journ. Geol. Soc, No. 42. p. Ixxix. 



