104 BOARD OF AGRICULTURE. 



• In illustration of the singular variety and juxtaposition of 

 rocks found upon my farm, I desire to call your attention to 

 the two varieties which I hold in my hands. One is a frag- 

 ment split from a bowlder weighing, perhaps, five tons, and 

 is very nearly pure quartz ; it is white and beautiful. The 

 other is a granitic iron-stone, broken from another bowlder of 

 equal weight, lying, perhaps, about two rods distant from the 

 quartz bowlder. How diflferent are those specimens physi- 

 cally and chemically? I have here other specimens which 

 more fully illustrate the dissimilarity iu the bowlder rocks 

 found at my farm. These rocks serve to impress upon our 

 minds the conviction that they do not belong to any one 

 locality, but have been brought from different, and in some 

 cases distant, points, by an agency the nature of which we 

 have no positive knowledge. Finding, as I have, specimens 

 of talcose slate at the farm of a variety which is supposed 

 to be peculiar to the mountains in northern New Hampshire, 

 I am led to ask. By what agency was this rock transported 

 from those distant localities? It certainly could not have 

 come by human hands. The same question may be asked of 

 the granites, the quartz rocks, etc. From whence came they, 

 and how ? 



I have said that we have no positive knowledge of the 

 method by which these rocks have been deposited upon 

 our farms ; but we do have very ijlausible and reasonable 

 theories which, in a measure, satisfy our inquiries. These 

 rocks afford evidence, not onlj^ that they have been broken 

 from bed-rock at distant points, but also that they have been 

 subjected to some grinding, polishing force, long continued. 

 You observe upon this rock which I have in my hands groov- 

 ings and striations which could only be caused by its having 

 been forced over another and harder rock, in some movement 

 to which it has evidently been subjected. This stone I picked 

 up on my hill, as it was thrown out of a trench by workmen, 

 and is only one of hundreds I have found bearing similar 

 markings. In the larger bowlders which are imbedded in the 

 soil, I find these groovings to have determinate positions ; that 

 is, the lines run for the most part in fixed directions, usually 

 north and south, or perhaps north-east and south-west, show- 

 ing that the movement in which the rocks were involved was 

 from the north towards the south in general. 



