No. 338.] 
7 
tive position of the same rock at a distance from any point of observa- 
tion. Such knowledge would be of immense importance in the vicini- 
ty of mineral beds, guiding the observer in his search, and directing 
him to higher or lower elevations, as the case may be. In this State, 
the direction or bearing of the stratified rocks is nearly east and west. 
By knowing the elevations at different points, a certain rock stratum 
can be exhibited in all its degrees of elevation, from the Hudson river 
to Lake Erie. In many instances, we may thus determine the thick- 
ness of important formations when portions of them are obscure and 
cannot be examined without excavation ; and also be able to state the 
depth at which any certain rock lies below the one we are investigat- 
ing ; for, though the connexion may be clear enough, the absolute 
thickness of the higher rock may need to be ascertained. Without this 
knowledge of elevations, the geological maps would necessarily be very 
imperfect ; but these once designated on the maps, their importance 
will be acknowledged in their practical application. For mere refe- 
rence, such a map will be of great value, as it will indicate the height 
above the sea of several points in every county in the State, and at the 
same time, the colours would indicate the rocks which occupy those po- 
sitions. 
Your committee behoving that the collection and preservation of the 
maps, plans, surveys and levels made in the construction of our public 
works, are very proper in reference to those works, as well as to the 
Geological Survey, have no hesitation in recommending the passage of 
a law for that purpose. 
The only remaining topic to be considered, is the necessity of pro- 
viding rooms of sufficient magnitude to contain a full and comprehen- 
sive collection of the natural productions of the State of New-York, and 
exhibit at one view, its animal, vegetable and mineral wealth. 
The want of such rooms has prevented the Geologists from arrang- 
ing and displaying the collections already made, during the winter 
months, when field labor cannot be performed. There have been ob- 
tained upwards of 400 boxes of specimens, which are now stored away 
in a rude and unsafe manner, in rooms temporarily assigned for that 
purpose. It may be fuither stated, that it is absolutely necessary to 
unpack and arrange these specimens before the survey can be com- 
pleted ; because if specimens should be found wanting, more time will 
