302 SKY. GEOLOGY. RED SANDSTONE. 



of gneiss. A space succeeds in which no rock can be 

 detected, vegetation and alluvial soil occupying the ground 

 in the interior, and gravel covering it on the sea beach. 

 It is not improbable that these conceal some conglomerate ; 

 this being the natural position of such a rock, of which, 

 in fact, portions are occasionally found in the interior 

 country adjacent, without any other assignable con- 

 nexions. 



This vacant space is succeeded by a yellowish quartz 

 rock, accompanied by a schist, which although it very 

 often presents the characters of a clay slate, yet, more 

 commonly exhibiting those of a fine graywacke, will pro- 

 bably be ranked with it by most geologists. I shall not 

 be anxious hereafter to distinguish the different varieties 

 of this rock, as the geological relations of all are the 

 same. 



The nature of the succession now described is so simple, 

 and so conformable to the received order of rocks, as to 

 lead to the natural conclusion, that the gneiss is regu- 

 larly followed by micaceous and by graywacke schist ; and 

 were the investigation suspended here, as might easily 

 happen, an observer would decide on it without hesitation : 

 yet he would in this instance, as perhaps in others, substi- 

 tute system for fact. 



Where these beds of schist first appear, they are con- 

 formable to the gneiss in dip ; but they almost immediately 

 become reversed, and are found dipping to the north-west, 

 yet without any change of character or direction. The 

 angle of the dip is her? from twenty to thirty degrees. Fresh 

 substances shortly after make their appearance, and a rock 

 with the characters, at times of quartz rock, and at others 

 of common hard sandstone, and of various colours, whitish, 

 blueish, or brownish grey, is found in repeated alter- 

 nations with the graywacke schist. Approaching towards 

 the end of Loch in Daal these beds become nearly hori- 

 zontal, the elevation varying from five degrees to ten, 

 but the dip continuing still westerly. Further on, it 



