524- Geological Society. 



A letter, dated Helsingfors, January 5th, 1841, from Professor 

 Nordenskiold to Mr. Lyell, " On Furrowed Rocks in Finland," was 

 then read. 



In consequence of Sefstrom's observations on the lines which 

 traverse the surface of the Scandinavian mountains *, Professor Nor- 

 denskiold has heen induced to attend to similar phsenomena in Fin- 

 land, and he states, that he has noticed lines on almost all moun- 

 tains from Lapland to the south of Finland, ranging with few devia- 

 tions from N.N.W. and N. to S.S.E. and S. On the highest cliffs 

 they are seldom visible on account of the surface being worn, but 

 wherever the rocks are overlaid with sand and earth the lines are 

 easily discovered on the covering being removed. Professor Nor- 

 denskiold has likewise discovered shallow furrows, from three to six 

 feet wide, on the surface of the north and south sand-ridges or pla- 

 teaux which separate the water systems of Finland. He has traced 

 them for more than fifty fathoms maintaining the same directions 

 as the lines upon the mountains, and he has noticed that they are 

 sometimes near each other. The localities mentioned in the letter 

 are — near the church of Kemi ; between Antila and Raukula post- 

 stations on the road from Tornea to Uleaberg ; and at a place in 

 Carelia, some miles from the iron-works at St. Anna in Suojerfoi 

 parish. 



In searching for iron-ore near Helsingfors, a shaft twenty feet 

 deep was sunk in alluvial soil ; and Prof. Nordenskiold observed on 

 the surface of some fragments which had been blasted from a rock 

 at the bottom of the shaft, similar lines to those which occur on the 

 mountains, but he was unable to determine their direction, the exca- 

 vation being filled with water and mud. As the rock was twenty 

 feet below the surface of the water in the Finnish Gulf, this fact, 

 Professor Nordenskiold says, proves that the lines which traverse 

 the mountains exist also at least twenty feet beneath the level of 

 the Gulf. Another phenomenon of this nature lately observed by 

 him is a furrowed rock of gneiss, not far from Porkala, but six 

 wersts from the shore. The rock is flat and not very large, and at 

 the height of nine feet above the medium level of the water, is one 

 of the round holes called by the Swedes, " Giants' Pots," but of an 

 unusually large size, being about three feet by two and a half feet. 

 It was somewhat larger within, and sixteen feet deep. Professor 

 Nordenskiold had the water and detritus which it contained taken 

 out, and found at the bottom numerous perfectly rounded stones 

 mixed up with the mud. The sides of the Pot were exactly ground, 

 and as resplendent as gneiss can be made. At the east side the 

 brim was somewhat rounded, and well marked with a number of 

 large, flat, east and west furrows, showing, in Professor Nordens- 

 kiold's opinion, " that the stones and waves had on that side driven 

 in the brim at the time of its formation." On the opposite side the 

 margin was quite sharp, as if the rock had been broken away since 



• [A translation of which appeared in Taylor's Scientific Memoirs, Part 

 9.— Edit.] 



