No. 50.] 61 
DELAWARE COUNTY. 
This county has heretofore proved to be still less rich in minerals than 
the preceding. A brine-spring was discovered near Delhi in 1833, and 
a boring of considerable depth v^ras made through the rock. I have not 
ascertained the strength of the water they obtained. According to Mr. 
Mather there are some deposites of bog-iron ore in this county which 
may hereafter prove to be valuable. He also states that copper ore is 
very extensively diffused although in small quantities.* There are more- 
over several mineral springs. 
DUTCHESS COUNTY. 
The mineral productions of this county are quite similar to those of 
Columbia, to which it is contiguous. There is no part of the State in 
which iron ore is more abundant or more advantageously wrought. This 
ore is almost always of the variety called hematite, which is sufficiently 
rich, and yields iron of an excellent quality. Beds of it have been 
opened in the towns of Fishkill, Unionvale, Dover and Amenia, from 
which several furnaces are contantly supphed. But from appearances 
which are presented in various places, there can be no doubt that new 
beds will hereafter be discovered, and that the supply of ore will be 
equal to any demand that may be created. 
There exist here, as in Columbia county, several localities of wad 
or earthy oxide of manganese ; some of these may hereafter turn out to 
be valuable. 
The marble quarries of Dutchess are numerous, and the quantity of 
this useful material is entirely inexhaustable. The beds are similar in 
their character to those of Stockbridge and Egremont, and are found 
in the towns of North-East, Dover, Pawlings, Beekman and Fishkill. 
But the only ones which are extensively wrought at present are those 
of Dover, a circumstance chiefly to be ascribed to the land transport 
which is required to bring the marble to market. 
The Dutchess county marble varies somewhat in its characters. It is 
almost always dolomitic, or composed of the carbonates of lime and 
magnesia in variable proportions ; sometimes it is large grained and 
quite compact ; at others it is fine grained and so loose in its texture as 
to be unfit for a building material. A specimen of this marble from 
* Letter to his Excellency Governor Seward, published in the newspapers in Sep- 
tember, 1839. 
