UNDER THE APPLE-TREES 



dot my native fields, there is here and there a black 

 sheep — a rough-coated rock much darker than 

 the rest, which the farmers call firestone, mainly, I 

 suppose, because it does not break or explode in 

 the fire. It is a kind of conglomerate, probably 

 what the geologists call breccia, made up of the con- 

 solidated smaller fragments of older crushed rocks. 

 The material of which it is composed is of unequal 

 hardness, so that it weathers very rough, present- 

 ing a surface deeply pitted and worm-eaten, which 

 does not offer an inviting seat. These rocks wear a 

 darker coat of moss and lichens than the others and 

 seem like interlopers in the family of field boulders. 

 But they really belong here; they have weathered 

 out of the place strata. Here and there one may find 

 their dark worm-eaten fronts in the outcropping 

 ledges. They were probably formed of the coarser 

 material — a miscellaneous assortment of small 

 thin water-worn fragments of rocks and mud and 

 coarse sand — that accumulated about the mouths 

 of the streams and rivers which flowed into the old 

 Devonian lakes and seas. They are not made up of 

 thin sheets like the other rocks, and seem as if made 

 at a single cast. They are as rough-coated as alli- 

 gators, and do not, to me, look as friendly as their 

 brother rocks. They stand the fire better than other 

 stone. The huge stone arch in my father's sugar 

 bush, in which the great iron kettles were hung, was 

 largely built of these stones. I think the early set- 



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