No. 161.] 
79 
My assistant in the survey of the 1st Geological District, Mf. 
Caleb Briggs, jun., has examined in detail the north coast of the 
west part of Suffolk county, and I may be allowed to quote from 
an abstract, some of his valuable observations upon important geo- 
logical phenomena of this part of the island. He did not com- 
mence his duties on the detailed surveys, until after the middle of 
Oct.; yet, the annexed extract shews his industry, as well as the 
care and accuracy of his investigations, during the short time that 
elapsed before winter set in. 
" The head lands and cliffs, on this part of the island, are con^ 
tinually wearing away, by the action of the sea; and the materials 
of which they are composed, consisting principally of clay, sand^ 
gravel and pebbles, are transported by tidal currents, and deposi- 
ted in other places." 
"Fully to understand the causes which have been in operation, 
and the effects which have been produced, reference should be 
made to a map on which are indicated all the indentations of the 
sea into the land; as creeks, inlets, harbours and bays; all islands, 
and all projection of the land into the sea; as necks, promonto- 
ries, &c. 
The tidal currents, in sweeping along the headlands and cliffs, 
undermine them, and transporting the materials of which they are 
composed, form ishoals, block up the mouths of small inlets and 
creeks, so as to form fresh water ponds, by preventing the ingress 
of salt water; throw up sand beaches in front of marshes; form 
sand spits across the mouths of harbours; and connect islands with 
each other and with the main island. 
"Huntington Harbour, certainly otie of the best on the island, 
is of alluvial origin.* By reference to the map of Long Island, 
it will be seen that this harbour is formed by two necks of land, 
Loyds' neck on the west and northwest, and Eaton^s neck on the 
east and northeast. Loyd's neck, which was originally an island, 
has been connected with the main island by a low sand-beach, now 
overflowed at high water: Eaton's neck was formerly a cluster of 
four islands, which have, in the same way, been connected with 
each other, and with the main island. A sand-spit one and one- 
* Huntington Harbor embraces within it three smaller ones, viz. Loyd's harbor, Cow- 
harbor, and one near the village in Huntington, not designated by name on Burr's Co. 
map. 
