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SCIENCE-GOSSIP. 



WEE CUMBR A E. 



By John Smith. 



(~\s June 17th, 1S93, the Geological and Natural 

 ^-"^ History Societies of Glasgow had an excursion 

 to the island of Little Cumbrae, at the south 

 entrance of the River Clyde. The weather was of 

 that fine quality so prevalent that year. The 

 reason for so much sunshine, which made 1893 

 a noted year, possibly lay in more than one cause. 

 There appeared to be less dust in the air and 

 fewer icebergs in the Atlantic. The fine weather 

 we had appeared to depend more on the extra 

 quantity of direct sunshine than on an increase 

 in temperature of the winds, for, with all the 

 heat during the day, they blew cold evening and 

 morning. 



On the Fairlie shore of the mainland, south of 

 Cumbrae, the calciterous sandstone and con- 

 glomerate is seen dipping, at a high angle, in 

 places almost in a perpendicular direction. To- 

 wards the hills, as they are ascended, especially 

 by the beds of the Fairlie, or Glen Burns, the dip 

 gets gradually flatter, till where the traps overlay 

 the sandstones it is reduced to the small angle of 

 ten or fifteen degrees. 



Crossing over to the island of Big Cumbrae, the 

 sandstone is seen to dip in an opposite direction to 

 what it does at Fairlie, showing that the firth at 

 this part is excavated in the position of a large 

 anticlinal bend in the strata, probably accompanied 

 by pitching. Sailing along the Big Cumbrae shore, 

 we note those two conspicuous features — the Lion 

 Rock (so called from its appearance) and the Diel's 

 Dyke, which are traditionally believed to be the 

 "lan'stills" of a large bridge that spanned the 

 firth from Cumbrae to Fairlie. In this instance 

 tradition must be founded on fable, as the two 

 objects in question are parts of trap dykes, cutting 

 through the sandstone. By marine denudation 

 these have been rendered conspicuous, the sand- 

 stone beds on either side of them being softer than 

 the dykes, having been denuded away. At the 

 south-east end of the Big Cumbrae a "plane of 

 marine denudation " is both conspicuous and ex- 

 tensive, going right up to the base of the sandstone 

 cliffs, and showing us that during the last raised 

 beach period the land, relative to the sea, must have 

 remained for a very long period at the same level. 

 In this raised beach, near Millport, the shell, Trochus 

 Uneatus—a species now extinct in the Clyde — is to 

 be found in some plenty, and was first discovered 

 there by the famous " Cumbrae Naturalist." This 

 shell still lives in the British seas, further south. I 

 found it not infrequently in the Ardrossan Shell 

 Mound, indicating the high antiquity of that mound 

 and the greater mildness of the climate enjoyed by 



the people who reared it, the remains of whose 

 feasts it forms a record. 



In going to the Wee Cumbrae in small boats we 

 pass the Allans — rocks in Millport Bay— on one 

 of which there is an old building said to have been 

 out up by the Government of the day, and 

 'manned" by Excise officers, who were to keep 

 a look-out on smugglers ; but one of the former 

 having had his hand cut off in attempting to 

 "board a smuggler," the "Government were de- 

 feated," and the excisemen were obliged to leave 

 the isle and the position to the smugglers. 



As we approach Wee Cumbrae, the terraced 

 appearance of the island becomes conspicuous. 

 This is owing to the successive outcrops of the 

 bedded trap which dips towards the north-east, a 

 direction the opposite to what it does in the hills of 

 the Ayrshire coast adjoining. Different also is the 

 dip from that at the south end of Bute, showing 

 that the rocks of this district, Bute to Dairy, had 

 at one time been thrown into a series of large folds 

 by lateral pressure, causing a doubling up of the 

 " crust." 



We land at the northern or Shanniwilly Point and 

 are immediately in the presence of Haco's Tombs, 

 situated on a small platform a short distance above 

 sea level. These are large cairns of stones said to 

 have been erected over the bodies of some of the 

 northern warriors who fell at the battle of Largs in 

 1263. Some sixty years ago two of them are said to 

 have been opened, when, with human bones, remains 

 of plated brass armour " resembling fish scales," 

 swords, etc., were got, as well as, at a lower level in 

 the cairns, more ancient urns filled with calcined 

 bones ; showing that this spot, probably historically 

 sacred, had been used as a place of sepulture by 

 different races of people separated from each other 

 by many centuries of time, and living under very 

 different states of civilization. Not far from the 

 Tombs is what may turn out to be a shell mound, 

 formed at a period when the inhabitants of the 

 country were in a very primitive state. 



After examining the rocks of the north end of the 

 island, which are mostly amygdaloidal, some of 

 the cavities being filled with very pure specimens 

 of Iceland spar ; we took to our boats again, and 

 rowed along the east coast as far as the castle. 

 The rocks forming the shore all along this tract are 

 trappean, with a rudely columnar structure, and at 

 parts the old sea cliffs form prominent features. 

 Having arrived at the castle which is built on a 

 small island or trap, we walk southward along the 

 shore and examine a small outcrop of sandstone. 

 It is the only bit of sandstone, or even of sedi- 



