I 
LETTER 
From W. W. Mather, transmitting his Fourth 
Annual Report. 
Brooklyn, Con, Dec. 27, 1839. 
To his Excellency William H. Seward. 
My dear Sir : 
I enclose herewith the Fourth Annual Report on tlie Geological 
Survey of the First District of the State. 
It contains the results of my observations on the economical geology 
of Sullivan, Ulster, Delaware, Greene and Schoharie counties. Many 
important facts have been observed, that were before unknown. The 
discovery of fine building stones and marbles, favorably situated for ex- 
ploration and transportation : the tracing the stratum of flagging stone 
rock to a great distance, a material that was supposed to be confined to 
a small area ; a similar fact in regard to the water limestone of Ulster 
county, and which is ascertained to be inexhaustible ; the discovery of 
extensive bodies of peat, a combustible second only in value and use- 
fulness to coal beds : the notice and discovery of mineral springs ; and 
the examination of supposed mines, the proprietors of which have been 
discouraged from the further expenditure of capital, where there were 
not indications to warrant exploration ; are among the useful results of 
the survey during the past season. 
I have the honor to remain. 
Very truly, your ob't serv't, 
W. W. MATHER, 
Geologist First District, New- York, 
[Assembly, No. 50.] 
