36 Transactions. 



aid of water ; but it is more likely to be the result of glacier 

 action. 



The glacier is not only a solid but a plastic body, and 

 when, in its slow but continuous and resistless motion, it 

 passes over an opposing obstacle it not only wears away its 

 prominent parts but applies itself equally to the depressions 

 which it presents. Again if we consider the relation which 

 subsists between the strias referred to and the polished sur- 

 face in which they occur we are furnished with another 

 important item of information, viz., that the former were 

 produced subsequently to the latter. If the striae had been 

 produced before the polishing action began, or even during 

 its progress, it is manifest that during that process they would 

 have been obliterated. It is noteworthy that the striae are 

 confined to one side, just what might have been anticipated 

 if produced by an iceberg. To allow of its submitting stead- 

 ily to the application of so great a force as is implied in the 

 formation of these striae it must obviously have been firmly 

 imbedded in the underlying substratum. It is at least un- 

 likely that it should have been subsequently raised from its 

 bed and submitted to a second similar process. Indeed it is 

 obvious that these striae were inflicted by the tooth of old 

 Father Time in the last stage of the Boulder's existence, just 

 before it was inten-ed in the grave, whence we have so recently 

 dug it. We have not yet, however, exhausted the sources of 

 our information. We have as yet only examined the exter- 

 nal features of our friend's character. 



Let us see if we may not learn something of the inner 

 life. On examining the internal structure of the rock we 

 ascertain Avithout much difficulty that it is silurian in char- 

 acter. This, however, supplies us at once with an important 

 item of knowledge, for we know that the nearest silurian 

 rock is to be found in the Tinwald Hills on the one hand, 

 or in the Galloway hills on the other, and the enquiry is 

 immediately forced upon us — How came it here ? If we 

 examine its contemporaries perhaps we shall be able to elicit 

 some items of knowledge. These we find to consist of silt. 



