50 GEOLOGY OF ARRAN. 



more difficult than the ascent of Goatfell, and the more ex- 

 citing that it is somewhat dangerous. Should a mist happen 

 to surprise us upon certain portions of the route, our situa- 

 tion might be very critical. How promising soever the day 

 may be, let the climber never enter these mountains without 

 a pocket compass. The mists come down so sudden and so 

 thick in this changeful climate that without it he will be 

 bewildered and lost amid the high cols and peaks, and huge 

 slippery granite sheets. With ordinary caution, and the use 

 of a correct compass, he has nothing to fear. True, he will 

 find neither house nor herd's shieling within the mountain 

 circuit; but directing his steps by the compass, he cannot 

 fail, in a walk of two or three hours at the utmost, to reach 

 the inhabited border, where a frank welcome will meet him 

 at every cottage door. But let him bear in mind that the 

 variation of the compass in Arran is now about 26J west of 

 true north, with a yearly decrease of 4' or 5'. To the geolo- 

 gist we would recommend to carry, besides his hammer, 

 indispensable at every step, a good clinometer with which to 

 note the varying dips and inclinations of the slate and sand- 

 stone, and the relations of these to the granite centre and 

 the numerous dikes. To the botanist, besides his vasculuin, 

 a field book will be very useful, for immediate pressure of 

 the delicate mountain plants. On this and most of our 

 excursions our departure will be taken from the shores of 

 Brodick Bay, the unrivalled grandeur and beauty of which 

 attract the greatest number of summer visitants. For a few 

 days' sojourn new inducements are now afforded by a well- 

 managed and spacious hotel, on a beautiful site at Invercloy, on 

 the south side of the bay. Here, and at Corrie and Lamlash, 

 steamers call several times daily during the summer months. 

 24. The rock on the shore at Invercloy is a conglomerate 

 of the age of the coal a member, in fact, of the coal forma- 

 tion. It was formerly classed as a lower member of the 

 New Red, but this view cannot now be maintained. The 

 inland cliff marking the old coast line is well seen on the 



