RAMBLES OF A GEOLOGIST. 313 



termined the fact for himselfj at the expense of many a fa- 

 tiguing journey, and many an hour's hard digging, than he 

 found that it had been ascertained long before, though, from 

 the very inadequate style in which it had been recorded, 

 science had in scarce any degree benefited by the discovery. 

 In 1802 the late Sir John Sinclair, distinguished for his en- 

 lightened zeal in developing the agricultural resources of the 

 country, and for originating its statistics, employed a mine- 

 ralogical surveyor to explore the underground treasures of the 

 district j and the surveyor's journal he had printed under the 

 title of " Minutes and Observations drawn up in the course 

 of a Mineralogical Survey of the County of Caithness, ann. 

 1 802, by John Busby, Edinburgh." Now, in this journal 

 there are frequent references made to the occurrence of ma- 

 rine shells in the blue clay. Mr Dick has copied for me the 

 two following entries, for the work itself I have never seen : 

 " 1802, Sept 7th. Surveyed down the river [Thorsa] to 

 Geize ; found blue clay-marl, intermixed with marine shells 

 in great abundance." " Sept. 1 2th. Set off this morning for 

 Dalemore. Bored for shell-marl in the ' grass-park ;* found it 

 in one of the quagmires, but to no great extent. Bored for 

 shell-marl in the ' house-park.' Surveyed by the side of the 

 river, and found blue clay-marl in great plenty, intermixed with 

 marine shells, such as those found at Geize. This place is sup- 

 posed to be about twenty miles from the sea j and is one in- 

 stance, among many in Caithness, of the ocean's covering 'the 

 inland country at some former period of time.'" 



The state of keeping in which the boulder-shells of Caith- 

 ness occur is exactly what, on the iceberg theory, might be 

 premised. The ponderous ice-rafts that went grating over 

 the deep-sea bottom, grinding down its rocks into clay, and 

 deeply furrowing its pebbles, must have borne heavily on its 

 comparatively fragile shells. If rocks and pebbles did not 

 escape, the shells must have fared but hardly. And very 



