638 FOURTH REPORT 1834. 



grauwack^ hills ; and thus it is that after the ejection of the 

 old red sandstone trap, along the sides and base of the grau- 

 Macke range, the more recent eruptions are more distant from 

 the hills, and among the more modern deposits of coal-mea- 

 sures. But still, these succesive iipheavings of trap, though 

 they have found an outlet among the softer rocks, may have 

 increased the elevation of the grauwacke at different periods, 

 without there being on these occasions any visible ei'uption 

 of trap among these hills. It is perhaps a confirmation of this 

 remark, that the old red sandstone conglomerate, which was of 

 course originally at the same general level along the base of 

 the grauwacke range, is now 800 and 900 feet higher in the 

 western parts of it, than at the sea-coast, and the rise is most 

 remarkably uniform and regular on proceeding inland from the 

 coast. At the sea-shore, as already stated, the conglomerate is 

 lifted upon the top of the trap, and dipping into the sea. About 

 two miles inland (at Foulden) it is about 150 feet above the sea; — 

 at old Melrose, in the valley of the Tweed, it is 300 feet above 

 the sea; — at Greenlaw, nearer the hills, it is 480 feet; — at Dod's 

 Mill, near Spottiswoode, 500 feet above the sea ; — at Norton, in 

 Lauderdale, 540 feet ; — at Carfrae Mill, still nearer the central 

 range, 640 feet ; — and at the foot of Soutra Hill, on both sides of 

 the ridge, (which is probably about 28 miles from the sea,) be- 

 tween 820 and 890 feet above its level. 



Since, however, the elevation of the country at these succes- 

 sive periods, corresponding to the three kinds of trap now visi- 

 ble in the district, there seems to have been a fourth, though it 

 is admitted that this fact is more problematical, and is sup- 

 ported by indications of a less decisive character. The vertical 

 coal-measures at the foot of Lamberton Hill, along the sea-coast, 

 have seen described. Immediately south of Burnmouth there 

 is a tract of table -land, now about 100 feet above the level of 

 the sea, which extends between the beach and the base of the 

 hill. It is in shape a triangle, the base of which runs along 

 the foot of Lamberton Hill for about 1^ mile, and the two sides 

 form the present sea-cliffs for about 3^ miles in extent. This 

 table-land consists of the vertical strata, which run parallel with 

 the base, and are seen at the two sides of the triangle, at the sea- 

 shore, running right across the table-land. It is not a little cu- 

 rious that these vertical strata should all have had their edges 

 worn down to a horizontal and level plain, just as would have 

 been the case if the rocks had been exposed to the action of 

 marine currents incessantly sweeping over their edges. When 

 the tide is far out, exactly the same appearance is presented 

 by the vertical rocks, which form the bottom of the shore, 



