Recent Exposure of a " Washout " of Strata. 395 



at Hailes Quarry, where the superincumbent shales and 

 underlying sandstone had been cut through to a depth of 

 60 feet, and to a width varying from 12 to 14 feet at the 

 surface, but gradually narrowing to only 2 or 3 feet at 

 bottom. It was a wedge-shaped gorge, smooth and polished 

 on the sides by ice and water action, and now filled with clay 

 and boulders, the produce of the glacial period during which 

 the washout had been excavated." This washout, and others 

 to which he alludes, Dr Page says were in fact old river 

 courses of the country before and perhaps during part of the 

 glacial period. 



I remember of seeino^ in 1869 or 1870 a cut out of the 

 sandstone exposed in the southern face of Hailes Quarry, 

 which had been filled in with boulder clay, and that to keep the 

 stones in it from falling and hurting the men working below, 

 a wall of masonry was built against it. The size of the cut 

 might be 20 or 30 feet in depth and 10 or 12 in width. It 

 was not wedge-shaped, but square at the bottom. It might, 

 however, be a portion of that described by Dr Page, in which 

 the wedge form had disappeared, as the sandstone was 

 quarried farther back from what it was in 1864. I have been 

 lately told by one of the foremen of Hailes Quarry that some 

 years ago they came upon a tunnel in the rock, formed by 

 water as they supposed, because in the bottom of it there 

 were pot-holes or whirlpools filled with stones, some of which 

 were large enough to be called boulders. At present (1890) 

 there is a space walled up same as the one I saw in 1869-70, 

 and the layers of sandstone above are disturbed as if they 

 had fallen into a hollow. This is probably the west end of 

 the tunnel. The whole of these washouts might be portions 

 of the river, I supposed, to account for the sand and gravel 

 bed with boulders under Kingsknowe Farm House, as 

 described in the paper on the "Ancient Lakes of Edin- 

 burgh," page 135 of this volume. 



Explanation of Plate. 



The Plate exhibits the washout in almost its whole extent, 30 to 40 feet. 

 Lowest bed seen is the sandstone in progress of quarrA'ing. Tlie plane on 

 which the split boulder rests is the surface of the sandstone after the shale 

 VOL. X. 2d 



