4 
GEOLOGY OF THE FOURTH DISTRICT. 
In our own geology, the first step towards this degree of perfection has been made in the 
groupings adopted in the Reports. This was all that could be accomplished for the present, 
when the whole subject was to be reduced from its former chaotic state, and while so much 
remained to be done in its other departments. The arrangement of the whole system in 
classes, orders and genera, will follow naturally, from what has been done, all the elements 
being prepared. 
The first object in the prosecution of this survey, has been to ascertain the existence and 
extent of the different rocky masses, their lithological characters, their mineral and fossil con¬ 
tents and other associations, and their order of succession, or the manner and order in which 
one rock is preceded or followed by another. Facts of this kind were collected throughout 
each mass from one extreme to the other, in many cases extending across the whole State. 
In this way only could the materials be obtained for forming a System, or presenting in their 
proper order and association the collections made in different parts of the State. Thus our 
rocks have been arranged, and each one holding its appropriate place in the series, its extent 
and its mineral productions are easily pointed out. The relation of any one mass to others 
of importance is thus readily seen, and also the relative position of the whole as regards the 
great Coal formation or Carboniferous system. 
Among the most important facts demonstrated in the progress of this survey, is that of the 
non-existence of the great Coal formation within the limits of New-York, except its lower 
member in a few detached points or outliers. This knowledge, though negative, is neverthe¬ 
less of great value ; having forever set at rest a vain expectation, which has cost an immense 
expenditure in time and money. When facts of this kind are fully understood and appre¬ 
ciated, the importance of the survey will be seen in the abandonment of all schemes of mining 
for coal and the precious metals, and the consequent quiet and satisfaction ever attendant on 
rightly directed enterprise. 
It is thus negatively, as well as by direct and positive discoveries, that science ameliorates 
the condition of mankind ; turning attention from useless and visionary pursuits, and directing 
it to that which yields a ready and satisfactory result for the expenditure of labor and time. 
And although the promulgation of scientific truths may restrain the vagaries of minds which 
delight to build the splendid air castles of suddenly acquired wealth, it will nevertheless direct 
man’s energies to sources where perseverance is sure to be crowned with rewards which a 
morbid fancy would crave at the commencement of the enterprise. From science alone will 
man learn his true interests, as regards his well-being in this world. 
In a report like the present, being the result of investigations commenced after much was 
already done, and where it is not always convenient to refer to the author, time and place, a 
short notice of what had been previously accomplished, and what was the condition of geolo¬ 
gical knowledge when the survey began, will show the manner in which our rocks have been 
studied heretofore, and afford an explanation of the comparatively little progress that had been 
made towards a correct classification of the same. 
Thirty-three years have elapsed since Mr. Maclure published his “ Observations on the 
Geology of the United States.” To him we are indebted for the first sketch of a system, 
