190 TIME'S INSTRUMENTS. CHAP. xm. 



"Fourth; they were once more in motion. The 

 abrading time came. The stupendous catastrophe oc- 

 curred, which drove them along to a new abode, and 

 during this period they suffered a diminution of their 

 surface. 



" Is it necessary to say more ? I state facts. Let 

 others theorise. 



"Many persons attribute the changes which have 

 occurred on the face of the earth, to Time. But what is 

 Time without his instruments ? Kain, frost, hail, snow, 

 ice these are his instruments. With these he rends 

 and brings down the mighty rocks even the eternal 

 hills. The Sea also is his one of his most efficient 

 workers. 



" A mighty mass of water must once have covered 

 the Sutherland mountains, and rolled down from them 

 ponderous boulders, tossing them about like playthings, 

 and throwing them far and near over Caithness. Thus, 

 a great boulder from Morven lies at Weydale, not far 

 from Thurso. Another lies at Slater's obelisk, on 

 Holborn Head. In short, I cannot tell how many more 

 there are. 



" But one thing seems evident. The boulder stones 

 owe their removal to the same causes which laid down 

 the blue boulder clay. They lie on its surface ; some of 

 them are embedded in its uppermost tier; others are 

 near the bottom. 



" But a truce ! I am still standing by the Freswick 

 Burn, and must trace it up before I set out homewards. 

 Well, I trace up the burn. I pass section after section, 



