RUM. GEOLOGY. 479 



rarely possible to land for the purpose of examining them ; 

 while they are at the same time inaccessible from above. 

 The geologist who wishes to make himself intimately 

 acquainted with this coast, even where it is more acces- 

 sible, as well as with many others throughout these 

 boisterous seas, must learn to despise the winds and the 

 waves. 



THE rocks of this island present examples both of the 

 stratified and unstratified classes ; and although I hope 

 to make their relations apparent, it is very difficult, even 

 with the assistance of the accompanying map, to mark 

 the regions which they respectively occupy. All the 

 care bestowed on the investigation is too often rendered 

 unavailing for that purpose by the incorrectness of the 

 maps and charts of these islands, by the total want of 

 villages or other points of reference, and by the difficulty 

 of obtaining the native names of the hills, rivers, and 

 promontories, which, in the absence of better marks, might 

 be made to serve this purpose. The reader must be con- 

 tent to receive his information in the best form in which 

 I am able to place it. 



The observations already made in Sky have so far 

 determined the order of arrangement of the stratified 

 rocks found there, as to serve for a basis in the descrip- 

 tion of those appertaining to Rum, which resemble them 

 so much in every essential circumstance as to leave no 

 doubt of their being both portions of one common deposit. 



It was shown that the red sandstone of Sky formed, 

 together with different beds of schist and quartz rock, 

 a great body of strata lying in a north-easterly direction and 

 dipping towards the south-west. The general resemblance 

 of the sandstone which constitutes a very large portion 

 of Rum to this, made it important to ascertain whether 

 they were parts of the same mass ; a circumstance to be 

 determined, partly by the bearing and dip of the strata, 

 and partly by the identity of the rocks preceding or 



