222 FORTT-THtRD REPORT ON THE StATE MuSEUM. 



the spring of 1884. A critical examination of the proof-sheet then 

 showed such deficieuces in the representation of drainage and other 

 important features, that it was impossible to lay down with accuracy 

 the limits of the geological formations. This condition of the map 

 was reported to Messrs. Bien & Co. 



In the meantime Major J. W. Powell, Director of the United States 

 Geological Survey, had begun the preparation of a geological map to 

 embrace the States of New York, New Jersey and Pennsylvania. To 

 aid this object, a copy of the uncompleted base made by Bien & Co., 

 together with manuscript and colored maps, and all information 

 possessed by myself, was freely furnished to the Director of the 

 United States Geological Survey. This map of the three States, 

 embodying all available, reliable information, has already been com- 

 pleted. In November last Major Powell placed at my disposal the 

 services of a very competent geological cartographer, Mr. W. G. 

 McGee, furnishing at the same time a base map from the United 

 States Survey Office, and he has carefully laid down on this map the 

 geological formations of New York so far as their limits and extent are 

 actually known and determined. A cojDy of this map will be com- 

 municated with the present rejDort, and its publication will remain 

 subject to the order of the Legislature. 



In the present connection I should not omit to refer to the geologi- 

 cal map of the State, published in 1843, at the close of the geological 

 survey. This map is published as the result of a survey which had 

 been continued for four years, a work beginning without any reliable 

 knowledge of the succession or geographical extent and distribution 

 of the geological formations embraced within the limits of the State. 

 The time allowed had been* insufficient for a thorough investigation 

 of the geology, and there were no maps available for laying down the 

 field work with the care and accuracy requisite. The map was the 

 product of four independent workers in the field, and in order to 

 harmonize the results of observation it became necessary to make 

 concessions and to accept modifications, both in nomenclature and in 

 geographic limitations, in order to compile an acceptable geological 

 map of the State. Rock strata of similar character and in near rela- 

 t on, were considered of the same age, though since that time distinc- 

 tions have been clearly shown. We had then no palaeontological 

 guide, or but a very imperfect one, and this want was not fully 

 apprehended or appreciated. The map should properly have been 

 entitled, a preliminary geological map of the State. 



That map, now more than forty years old, has served its purpose, 

 as all preliminary maps do, by giving an expression to the great 



