ON THE GEOLOGY OF THE ISLAND OF AQUIDNECK. 527 
change of land is quite as favorable to the collection of sand 
_ along the shore line as the process of elevation. In general the 
_ existence of great quantities of sand along an ocean shore may 
be taken as probable evidence of recent geological movements 
_ which have enabled the sea to work over a great amount of débris, 
of which it has left the heavier part where it found it, and has 
heaped up the lighter parts where its currents naturally swept them. 
Bay has less drift than exists in the regions further to the north- 
ward; it also has few stretches of shore which furnish quantities 
of sand to eroding agents and none of those great rolling beaches, 
such as abound to the northward where thousands of tons of peb- 
bles, rushing to and fro under the beat of the waves, are gradually 
ground into sand and mud. The rocks exposed about Narragan- 
set Bay to the full surge of the ocean are mostly stubborn resist- 
ers of the waves, and where masses break away they generally 
fall into deep water where they are not ground up by the waves. 
There are no currents working along the shore, which are capable 
of transporting sands from either the Cape Cod shore or the great 
masses of Long Island. - We see that circumstances have cooper- 
ated to keep the inlets of this diversified and beautiful region of 
_ ur shore free from the overwhelming sands, which in the regions 
è little to the east or west would have soon closed or effaced 
them, Nothing can be more strikingly contrasted than the topo- 
graphical results of water in its solid and its fluid states. Where 
W moves from the land in the solid phalanx of the glacier it rends 
a coast into shreds, as ragged as a cloud blown out by the wind. 
“n the sea with the ever varying action of waves and currents, it 
_ Works to restore the uniformity it destroyed before. Its waves dig 
down the heights and fill up the hollows, its currents build moles 
cross. the inlets and give them over to the agents which speedily 
fonvert them to marshy plains. i 
pat the close of each of the many great ice periods in the earth’s 
“ory the fretted line of the fiord zone was probably swept 
clear of its débris of all kinds. Then began the process of occlu- 
"A Which continued until the ice came again to renew its work. 
| Fecognizing the harbors and inlets of Narraganset Bay as 
al work, we get an example of the agent which has given 
northern part of Europe have been universally maritime is 
It will hereafter be shown that the whole region of Narraganset . 
aa , iths of the havens of our seaboards. That the people of - 
