158 THE BOULDER CLA Y. CHAP. XIL 



Miller, he began his researches into the boulder clay* of 

 Caithness. " I had seen the boulder clay," says Hugh 

 Miller, " characteristically developed in the neighbour- 

 hood of Thurso, but, during a rather hurried visit, had 

 lacked time to examine it. The omission mattered the 

 less, however, as my friend Robert Dick is resident in 

 the locality ; and there are few men who examine more 

 carefully or more perseveringly than he, or who can 

 enjoy with higher relish the sweets of scientific research. 

 I wrote to him regarding Professor Forbes's decision on 

 the boulder clay of Wick and its shells ; urging him to 

 ascertain whether the boulder clay of Thurso had not 

 its shells also. And almost by return of post I received 

 from him, in reply, a little packet of comminuted shells, 

 dug out of a deposit of the boulder clay, laid open by 

 the river Thurso, a full mile from the sea, and from 

 eighty to a hundred feet above its level. He had 

 detected minute fragments of shell in the clay about 

 twelve months before; . . . but his dread of being 

 deceived by mere surface shells, carried inland by sea- 

 birds for food, prevented him from following up the dis- 

 covery." j- 



But now that Hugh Miller inquired about the 

 existence of sea-shells in the boulder clay, Dick pro- 

 2eeded to follow up his investigations with the keenest 



* Clay of the Glacial or Drift epoch, usually mixed with large stonea 

 or boulders. The boulders have been dropped in deep water from floating 

 ice, and have settled in the clayey silt. The boulder clay is widely 

 spread throughout Great Britain. 



f Hugh Miller's " Rambles of a Geologist," in Cruise of Ike Betsy, 

 pp. 311-12. Ed. 1873. 



