ANNIVERSARY ADDRESS OF THE PRESIDENT. 205 



along the Norwegian coast to beyond Drontheim, a distance from 

 Gothenborg of more than 500 miles. One remarkable case he gives, 

 that occurs to the north of Drontheim, where the furrows are cut 

 horizontally in a pudding-stone rock of pebbles of granite and 

 quartz, the hardest of which are cut through as clean as the softer 

 argillaceous cement. The eroding tool has acted to the length of 

 forty-five metres (about fifty yards), on a surface inclined from 45° 

 to 50°, and with a breadth of from four to five metres (thirteen to 

 sixteen feet). But my limits oblige me to refer you to the memoir 

 itself, and to the report of the discussion to which it gave rise, for 

 many most interesting facts, and some important views as to the 

 causes of these remarkable phaenomena*. For the same reason I 

 can only very briefly allude to the descriptions contained in several 

 parts of Mr. Lyell's ' Travels,' of the boulder formation, the erratic 

 blocks, and the furrowed surfaces that are met with over a great 

 part of the northern regions of North America, presenting many 

 features identical with those of Northern Europe. 



In Europe the boulder formation has not been traced farther 

 south than 52° north latitude, but a similar kind of detritus, 

 sand, clay, gravel, and rounded blocks of great size, cover a con- 

 siderable extent of country in the neighbourhood of Boston, which 

 is ten degrees farther south, or about the latitude of Valencia in 

 Spain. It is not found within the range of the Alleghany Moun- 

 tains ; but blocks again appear on their western side, near the Ohio 

 river, in latitude 40°, and some scattered blocks have reached Ken- 

 tucky, the northern boundary of that state, in latitude 38^°. How 

 far a boulder formation, erratic blocks and furrowed rocks extend 

 beyond the valley of the St. Lawrence, we have yet to learn ; but the 

 scanty information we do possess leads us to infer that they exist on 

 the shore of the Arctic Sea. 



Near Boston the boulder formation has been pierced to a depth 

 of more than 200 feet without the solid rock having been reached ; 

 and although mainly composed of the materials of neighbouring 

 rocks, huge rounded blocks brought from a great distance rest upon 

 them or are buried in them. Here, as in Russia and Denmark, we 

 have a boulder formation composed of materials that have not been 

 far-travelled, intermixed, in some degree, with, but more frequently 

 covered by that of northern origin. An instance of this last occurs 

 at Brooklyn, near New York. 



In the United States, Canada, and Nova Scotia, where the gravel 

 or drift has been removed, the rock immediately subjacent is very 

 frequently furrowed and striated, and here and there flattened domes 

 of smoothed rock (I'oches moutonnees) are met with. The furrows 

 have been found in the New England Hills at all heights, even to 

 as much as 2000 feet. In one place, on the summit of a high hill 

 of sandstone, Mr. Lyell saw an erratic block of greenstone 100 feet 

 in circumference. The erratic blocks and boulder formation have 

 been transported southwards along the same lines as are marked out 



* Bulletin de la Soc. Geol. de France, tome iii. p. 65, 



