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REV. A. W. EOWE ON THE 



out upon the land or into the lanes, or are carted off to the farmyards 

 to repair walls or to serve as mounting-stones, or to fill up holes 

 in front of the doorways. And upon comparing those which I know 

 have been taken out of the Boulder-clay with the rocks which lie 

 upon the surface, I have found them to be, as a rule, so precisely 

 similar in character as to leave no room for doubt that the great 

 majority of them belong to the same series. On the other hand, there 

 are certain fragments of rock found upon the surface whose presence 

 there is doubtless due to other causes than the glacial drift, such as 

 fragments of Jurassic limestone and of hard chalk rock (used in earlier 

 times for building churches and priories), and pieces of a trachytic rock 

 closely resembling that which the Romans imported from Germany for 

 use as millstones. Yet, making all allowance for such fragments, there 

 still remain the facts that an immense number of boulders and frag- 

 ments, some of very large size and nearly all polished and smoothed 

 and rounded in a remarkable manner, are found lying on the surface, 

 which cannot conceivably have come so far from where they are 

 found in situ in any other way than as having been included in the 

 drift ; and that, wherever the surface of the ground is being broken 

 up at the present day, exactly similar boulders and fragments of rock 

 are being dug up and left lying on the surface. These do not, however, 

 appear to belong to the same period as the beds of gravel ; for not only 

 is the general appearance of the stones in the gravel-pits very different 

 from the appearance of those found on the surface, but also, though 

 quartzites, sandstones, and quartz-rocks abound both in the gravels 

 and on the surface, yet I have not found any fragments of hard crystal- 

 line limestone or of Jurassic limestones in the gravel-beds, and only two 

 or three fragments of dolerite, and these so decomposed that only a very 

 small core was still crystalline ; whereas, among the stones on the 

 surface, blocks of hard crystalline limestone and of Jurassic limestone 

 are most abundant, and there are a very great number of boulders of 

 dolerite, some of considerable size, of which the crystalline components 

 are as sharp and fresh as if they had just been struck off from an almost 

 unweathered mass. The very great variety in these rocks makes it 

 very difficult to classify them at all satisfactorily ; so much so, that 

 after having examined several hundred pieces, and having made 

 microscopic sections of at least one hundred and fifty, I find that I 

 can do little more than form them into groups, and point out the 

 common features of each group, making special mention of any 

 specimen which seems to require it. 



Granite. — It is somewhat more convenient to take the igneous 

 rocks first and to consider the sandstones and limestones afterwards. 

 And the first group of igneous rocks should have included the granites 

 or orthoclase-quartz-mica rocks ; but though I have searched care- 

 fully for them, yet I have not been able hitherto to find a single 

 specimen of granite. This is the more remarkable, because I under- 

 stand that rocks of this class are not unfrequently found iu the 

 Boulder-clay both in Norfolk and in Lincolnshire. 



Syenite. — The rocks of this class are also very rarely met with. 

 At present I have found only two small specimens (nos. 1, 2). Of 



