562 HISTORY OF THE OUTER HEBRIDES. 



the Conglomerate, leaving only a small island in the harbour 

 as an outlier. The sea has fretted the base of the cliffs 

 into arches and caves, especially on the north-west shore of 

 the Broad Bay, where the exposure to the north-east is 

 open sea. Macculloch, who had the fine eye of an artist 

 well as the keen glance of a scientific observer, notes th; 

 " caves of various dimensions are found in these cli] 

 offering subjects of considerable beauty to the pencil of 

 artist" 



The cliffs of the Conglomerate, when seen from the south- 

 east, show rude lines of stratification dipping at angles 

 the south-west from 30 degrees to 40 degrees. As the dip 

 the adjacent gneiss is north-east, we have the Conglomeral 

 thus lying unconformably upon it. The dip of the gneiss 

 in the immediate neighbourhood is almost vertical ; at the 

 junctions at Chicken Head, Garrabost, and Gress, I found 

 the angle to be about 80 degrees. At the Chicken Head 

 junction the Conglomerate is seen for a short distance, and 

 at low-water, resting on a pediment of the gneiss formed 

 by the truncated edges of the strata, and sloping to the 

 south-west, parallel to the stratification lines of the Con- 

 glomerate above. A glimpse is thus given of the shelving 

 shore upon which the Conglomerate accumulated as a 

 beach. The steep cliffs at the junctions at Garrabost and 

 Gress, the high angle 60 degrees at the junction near Lewis 

 Castle, and the south-west dip of the stratification, seem to 

 indicate that the conditions which still hold good in the 

 far-reaching sea-lochs of Lewis, as to the deposition of 

 coarse boulder beaches, held good in Archaean ages, if the 

 Conglomerate goes that far back. If the same relative 

 levels existed then as now, the sea which breached those 

 ancient cliffs to form the Conglomerate at their bases, must 

 have submerged almost all the tract of open land to the 

 south-west, lying between Loch Roag and the hills of Uig 

 and Harris. This "if" with its consequent is however 

 altogether irrelevant to the main point of interest in this 

 subject. 



A cursory examination of the Lewis Conglomerate shows 



