508 Geology and Magnetism. 



shores of the Hebrides are collected seeds of several plants the 

 growth of Jamaica, Cuba, and the neighbouring continent. The 

 most striking circumstance, perhaps, is that of the wreck of an 

 English vessel, burnt near Jamaica, having been found on the coast 

 of Scotland. From the account of Captain Parry, it appears that 

 there is also a great quantity of timber cast by the sea upon the 

 northern coast of Spitzbergen. Timber is found floating in large 

 quantities in the north polar seas, and much of which is thrown 

 ashore on the northern side of Iceland ; some of which appear to be 

 of the growth of Mexico and Brazil. This question has engaged a 

 good deal of attention, and has been considered difficult to explain ; 

 but by admitting the general northward tendency of the ocean the 

 question is easily solved. 



" Ice is fallen in with much sooner in sailing towards the south 

 than it is in approaching the north pole. The dry lands or the large 

 continents are more or less pointed towards the south, whereas the 

 northern parts are more or less ragged and crowded about the 

 northern pole ; in a word, all observed facts tend to prove that the 

 ocean moves from the south pole towards the north. (Plate V.) 



" If, then, such an action is actually going on in the great terres- 

 trial battery, its effects will not be confined to that of the ocean, but 

 will also produce corresponding effects on the solid and semi-fluid 

 part of the earth. Such an effect is apparent in the meridional la- 

 mination of the crystalline rocks, as shown in Plates IV. and V. 



11 In South America we find the whole region laminated in a north 

 and south direction, subject of course to great contortions from 

 various local disturbances. This lamination forms those kind of 

 rocks known by the name of gneiss and schistose, being in fact a modi- 

 fication of the granitic base, produced by the polar laminating action, 

 and not, as it is erroneously considered, the result of a mechanical 

 sedimentary action. The planes of these meridional laminations 

 are generally more or less vertical, and are often seen cutting 

 through sedimentary beds at right angles to the seams of deposition, 

 and thus showing their independent and subsequent origin. Nor is 

 this meridional structure confined to South America, but extends to 

 the north, subject of course to great bends from numerous mecha- 

 nical resistances. 





