350 RAMBLES OF A GEOLOGIST. 



thousands every year ;* and there are few of my northern 

 readers who have not heard of the short trip taken nearly 

 half a century ago by the boulder of Petty Bay, in the neigh- 

 bourhood of Culloden. 



A Highland minister of the last century, in describing, for 

 Sir John Sinclair's Statistical Account, a large sepulchral 

 cairn in his parish, attributed its formation to an earthquake ! 

 Earthquakes, in these latter times, are introduced, like the 

 heathen gods of old, to bring authors out of difficulties. I 

 do not think, however, and I have the authority of the old 

 critic for at least half the opinion, that either gods or earth- 

 quakes should be resorted to by poets or geologists, without 

 special occasion : they ought never to be called in except 

 as a last resort, when there is no way of getting on without 

 them. And I am afraid there have been few more gratui- 

 tous invocations of the earthquake than on a certain occasion, 

 some five years ago, when it was employed by the inmate of 

 a north-country manse, at once to account for the removal 

 of the boulder-stone of Petty Bay, and to annihilate at a blow 

 the geology of the Free Church editor of the Witness. I had 

 briefly stated in one of my papers, in referring to this curious 



* " In the river St Lawrence," says Sir Charles Lyell, "the loose ice 

 accumulates on the shoals during the winter, at which season the water is 

 low. The separate fragments of ice are readily frozen together in a climate 

 where the temperature is sometimes 30 below zero, and boulders become 

 entangled with them ; so that in the spring, when the river rises on the 

 melting of the snow, the rocks are floated off, frequently conveying away 

 the boulders to great distances. A single block of granite, fifteen feet long 

 by ten feet both in width and height, and which could not contain less than 

 fifteen hundred cubic feet of stone, was in this way moved down the river 

 several hundred yards, during the late survey in 1837. Heavy anchors of 

 ships, lying on the shore, have in like manner been closed in and removed. 

 In October 1836, wooden stakes were driven several feet into the ground, 

 at one point on the banks of the St Lawrence, at high-water mark, and 

 over them were piled many boulders as large as the united force of six 

 men could roll. The year after, all the boulders had disappeared, and 

 others had arrived, and the stakes had been drawn out and carried away 

 by the ice." (" Elements," first edition, p. 138.) 



