No. 161.] 
63 
To bring this subject home to the mind, I will state briefly the 
grounds for the above opinion. There are more than 12,000 square 
miles in my district, which contains 21 counties. Five months in 
the year is as much time as can be passed to advantage in the 
field, and no more than 20 days can be calculated on per month 
for field labor, which gives 100 days per annum for active duty in 
the field, or 400 days in 4 years; hence, as there are more than 
12,000 square miles in my district, I shall be obliged to examine 
more than 30 square miles per day. No one can examine so 
great an area, in the allotted time, except in the most imperfect 
manner, by distant views; and this method can serve to develope 
only a part of either the economical or scientific geology. The 
greatest value of the survey, in an economical point of view, will 
result from detailed examinations of the soil, rocks, mineral springs, 
ores, beds of peat, clay, marl, &c. and it is greatly to be desired 
that every farm should be examined, where there is the slightest 
prospect of finding any thing of value to the owner, and this can- 
not be effected without an increased time, or a greater number of 
assistants. 
11. RECONNAISSANCE. 
The reconnaissance of the 1st or S. E. geological district of 
the State of New- York, (embracing Long-Island, Staten-Island, 
and the territory from the head of Lake Champlain, southwesterly 
to the Delaware river, thence along Pennsylvania, New- Jersey, 
Connecticut, Massachusetts and Vermont lines, to the place of 
commencement,) has shewn, that a great number of valuable mine- 
rals and rocks occur in abundance, in almost every part of it, and 
that the facilities for applying them to useful purpose are very 
great. Rocks suitable for rough and dressed building stones, easi- 
ly quarried, and which will stand the vicissitudes of our variable 
climate, are abundant in the vicinity of the Hudson river, from 
Cornwall to New-York, and are convenient to water transporta- 
tion. 
Rocks, suitable for flagging stones and roof slates, are found in 
the valley of the Hudson, from Cornwall to Sandy-Hill. 
White and clouded marbles of various qualities, some of which 
are durable, abound on the east side of the Hudson, below the 
Highlands. Dark colored, compact, variegated and conglomerate 
marbles, occur in various localities, between the Highlands and 
