366 MAN OF SCIENCE. 



which you pushed the crumbs before you, a number of 

 minute streaks corresponding with the minute ridges of 

 the skin. Such are the marks on what may be termed 

 the cleared table here. Wherever the rock is laid bare 

 we see it all furrowed and channeled with grooves and 

 scratches, in the bearing of the moraines on the hills. 

 These workings give a very high idea of the antiquity 

 of the oolite, comparatively modern as the oolite is in 

 the chronology of the geologist. When the ponderous 

 ice slid over it, it was in exactly the same fossil state 

 that it is now. The rock, a white sandstone, abounds 

 in fossils, that are but hollow casts ; and wherever one 

 of these casts occurs, the stone is weaker than where 

 there is none. Now, we find that the glacier discovered 

 this weakness, and in many places broke out the hollow 

 casts that are nearest the surface, leaving within the 

 fragments that it pressed down into them. 



' I did not take the beaten path to Loch Brora, but 

 struck upon it through the moor, and passed on my 

 way through a large peat mass, roughened at present by 

 the winter fuel of the people of Brora. There are a 

 few scattered moraines that rise over its dingy level, and 

 which must have been there long ere the morass itself 

 had any existence. And yet in this morass large fir- 

 trees are found, the remains of one of our ancient forests. 

 I saw in one pit several huge blocks laid bare ; they 

 seemed originally to have been trees of that short- 

 stemmed, bee-hive-looking class I have seen in some 

 places in the central Highlands. They never assume 

 that form save when standing far apart in a compara- 

 tively open country. Here are degrees of antiquity for 

 you ; the moraines are as of yesterday when compared 

 with the oolite, and the ancient forests as of yesterday 

 when compared with the moraines. 



