of Edinburgh, Session 1883—84. 
791 
to this block there is another Conglomerate boulder of smaller size, 
with an ancient cup-shape hollow on its surface, apparently artificial, 
4 inches in diameter and J inch deep. Height above sea 190 feet 
(Sixth Report, p. 25). 
No Old Red or Conglomerate ranks in island. Nearest are at To- 
ward Point and Rothesay, from 12 to 20 miles across the sea to N.W. 
Split Boulder f first mentioned by Smith of Jordanhill, 
visited. Lies at sea-level, on rocks much smoothed and striated, 
forming east side of a trough, axis of which runs N.E. by N. Some 
of the striae are continuous for 30 yards. Striating agent must 
have moved from due north (Sixth Report, p. 25). 
Ailsa Craig, a mass of white p.orphyry, reaches to a height of 1114 
feet. At a height of 600 feet, on north side, there is a bed of clay 
mixed with sand of a red colour, derived probably from the debris 
of the Old Red Sandstone rocks of Arran, Big Cumbrae, Rothesay, 
and Toward ; — ^all situated to the N. and N.W. Pebbles of granite 
and quartz said to have been seen on the Craig (Sixth Boidder 
Report, p. 23), 
Arran, Island of. — (1) In Brodick Bay (East Coast), no boulders ; 
but along coast, to north and also to south, numerous and large 
boulders. 
Corriegill. — Boulder of grey granite, has longer axis and sharp 
end to N.W. Same kind of granite in Goatfell mountain, distant 
4 miles bearing N.N.W. 
Another boulder, 12x9x8 feet, half a mile to north, has its longer 
axis N, and S. 
(2) Near Carrie, two large boulders of granite sit near each other 
on plateau or terrace, about 93 feet above sea. Largest may weigh 
about 620 tons. Longer axis and sharpest end point N. by W. 
Rock on which it lies is Carboniferous sandstone. These two 
boulders must have been carWec?,— there being no adjoining hill 
rom which they could fall. Goatfell bears from them W. by S., 
and is distant about 3 miles. By a glacier they could not have been 
carried, as they are not in a valley, or near any valley from which 
a glacier could have issued (Sixth Report, p. 21), 
(3) To the north of Corrie, about 2 miles, the road passes a large 
boulder on the sea-shore called the “ Catstane,^' whose weight is esti- 
mated at 362 tons. 
