CHAP. xin. EXAMINES BOULDER CLAY. 185 



most important fact ; and it is elicited and brought to 

 light through your own request to me to make these 

 examinations. 



" Look at the map. There is a long stretch of country 

 between Harpsdale and Freswick, and yet both contain 

 fossils of the Oolite, chalk and flint, and a great variety 

 of stones common to both. Nor must you suppose that 

 a hundredth part has yet been found. No, no ! What 

 avails a hasty journey of mine ? Comparatively nothing. 



" I looked for my big bone of the first journey, in- 

 tending to send it up to Edinburgh. But it was gone, 

 as I half expected it to be. It has been swept into a 

 deep pool, perhaps carried out to sea. To the best of my 

 skill this section is stratified, and is a mixture of blue 

 and red boulder clay, with the red predominating. 



" After satisfying my curiosity at this section (from 

 twenty to twenty-four feet in height), I left it and went to 

 examine the strata and section at the small bridge. I 

 found that the strata, when wet, looked blood-red ; and 

 the clay resting on it dark blue. The rest of the section 

 seemed to be a mixture of red and blue boulder clay, 

 containing broken shells. I have a piece of the clay and 

 the strata in contact, for the purpose of sending to you 

 at Edinburgh. 



" Observing a small stream joining the main burn, 

 I turned into it ; and found that here too, blue boulder 

 clay lay thicker than the stream had yet cut down to. 

 Shells of Cyprina and Turritella were very abundant. 

 T traced the stream up until it seemed to terminate in a 

 shallow ditch. Eecrossing, in a direct line, to the burn 



