120 THE CRUISE OF THE BETSEY j OR, 



CHAPTER VIII. 



THE geology of the island of Rum is simple, but curious. Let 

 the reader take, if he can, from twelve to fifteen trap-hills, 

 varying from one thousand to two thousand three hundred 

 feet in height ; let him pack them closely and squarely to- 

 gether, like rum-bottles in a case-basket ; let him surround 

 them with a frame of Old Red Sandstone, measuring rather 

 more than seven miles on the side, in the way the basket sur- 

 rounds the bottles ; then let him set them down in the sea a 

 dozen miles off the land, and he shall have produced a se- 

 cond island of Rum, similar in structure to the existing one. 

 In the actual island, however, there is a defect in the inclos- 

 ing basket of sandstone : the basket, complete on three of 

 its sides, wants the fourth ; and the side opposite to the gap 

 which the fourth should have occupied is thicker than the 

 two other sides put together. Where I now write there is 

 an old dark -coloured picture on the wall before me. I take 

 off one of the four bars of which the frame is composed, 

 the end-bar, and stick it on to the end-bar opposite, and then 

 the picture is fully framed on two of its sides, and doubly 

 framed on a third, but the fourth side lacks framing altogether. 

 And such is the geology of the island of Rum. We find the 

 one loch of the island, that in which the Betsey lies at an- 

 chor, and the long withdrawing valley, of which the loch is 



