S74 /. Croll. — Boulder-clay of Caithness. 



Again, that the ice, after passing down the Baltic, turned to the 

 right along the southern end of Gothland, is shown by the direction 

 of the striae and ice-groovings observed on such islands as Grothland, 

 Oeland, and Bornholm. Sir E. Murchison found that the island of 

 Gothland is grooved and striated in one uniform direction from N.E. 

 to S.W. " These groovings," says Sir Eoderick, " so perfectly 

 resemble the flutings and striee produced in the Alps by the actual 

 movement of glaciers, that neither M. Agassiz nor any one of his 

 supporters could detect a difference." He concludes, however, that 

 the markings could not have been made by land-ice, because Goth- 

 land is not only a low, flat island in the middle of the Baltic, but is 

 " at least 400 miles distant from any elevation to which the term of 

 mountain can be applied." This, of course, is conclusive against the 

 hypothesis that Gothland and the other islands of the Baltic could 

 have been glaciated by ordinary glaciers ; but it is quite in harmony 

 with the theory that the Gulf of Bothnia and the entire Baltic were 

 filled with one continuous mass of land ice, derived from the drainage 

 of the greater part of Sweden, Lapland, and Finland. In fact, the 

 whole glacial phenomena of Scandinavia are inexplicable on the 

 hypothesis of local glaciers. 



That the Baltic was completely filled by a mass of ice moving 

 from the north is further evidenced by the fact that the mainland, 

 not only at TJpsala, but at several places along the coast of Gothland, 

 is grooved and striated parallel to the shore, and often at right 

 angles to the markings of the ice from the interior, showing that the 

 present bed of the Baltic was not large enough to contain the icy 

 stream. For example, along the shores between Kalmar and Karls- 

 krona, as described by Sir Eoderick Murchison and by M. Horbye, 

 the striations are parallel to the shore. Perhaps the slight obstruction 

 offered by the island of Oeland, situated so close to the shore, would 

 deflect the edge of the stream at this point over on the land. The 

 icy stream, after passing Karlskrona, bent round to the west along 

 the present entrance to the Baltic, and again invaded the mainland, 

 and crossed over the low headland of Christianstads, and thence 

 passed westward in the direction of Zealand. 



This immense Baltic glacier would in all probability pass over 

 Denmark, and enter the North Sea somewhere to the north of the 

 Eiver Elbe, and would then have to find an outlet to the Atlantic 

 through the English Channel, or pass in between our eastern shores 

 and the mass from Gothland and the north-western shores of Europe. 



Taking all these various considerations into account the conclusion 

 is inevitable that the great masses of ice from Scotland would be 

 obliged to turn abruptly to the north, as represented in the diagram, 

 and pass round into the Atlantic in the direction of Caithness and 

 the Orkney Islands. 



If the foregoing be a fair representation of the state of matters, it 

 is physically impossible that Caithness could have escaped being 

 overridden by the land-ice of the North Sea. Caithness, as is well 

 known, is not only a low, flat tract of land, little elevated above the 

 sea level, and consequently never could have supported large 



