MAKING THE ROCK BOTTOM. 1 9 



by the sea. Patches are to be found along Nichols Ave- 

 nue on both sides. Some is on Beach Island, near Brush 

 Island. It crops out of the side of Kent's Rocks at the 

 Cove. Widow's Rock, on the southeast side of Beech- 

 wood Street, a few hundred yards from King Street, is an 

 outcrop of diorite. There is a ledge of it near the foot of 

 Turkey Hill, where the stone crusher has been munching 

 it to make roadways for men so many millions of years 

 since nature made it in the bowels of the earth. 



It will be observed by close inspection that the patches 

 of diorite are enclosed usually in the first or outer granite. 

 In some cases there are lumps of it like plums in a pud- 

 ding ; and they bear the appearance of having been frag- 

 ments broken and mixed into a plastic magma. The cor- 

 ners are melted off, and the pieces are seen arranged 

 lengthwise with the flow structure. These pieces and 

 patches of diorite are accordingly the first formed of all 

 the rock our town affords. Nothing is older ! A man 

 who stands upon a mass of it has for his support the most 

 venerable of all nature's traditions in Cohasset. This dio- 

 rite and these three kinds of granite compose all the solid 

 rock of Cohasset, with the exception of the black dikes, 

 which are to be described presently. 



They are called plutonic rocks, because of being formed 

 so deep down beneath the surface of the earth, where 

 Pluto was fabled to have fashioned things in nature's 

 smithy. 



They are also called igneous rocks, because they were 

 formed out of melted stuff. Some kinds of granite are 

 said to have been formed by the slow changing of crystals 

 without any melting, from some sedimentary rock like 

 schist or gneiss ; but the granite of Cohasset was un- 

 doubtedly crystallized from a molten mass. 



Other localities, Hingham and Weymouth and Brain- 

 tree, to the west of us, have great ledges of shale or slate 

 or conglomerate that are neither igneous nor plutonic, 



