Page:Popular Science Monthly Volume 48.djvu/441

Rh the State of New York, and in the organization of the staff for carrying on that work Dr. Emmons was appointed by Governor Marcy to the charge of the second district, which included the northeastern counties of the State. This district was chosen by Dr. Emmons as a field more especially interesting to him on account of its mineral localities and minerals, and giving him a field more congenial to his tastes and experience. He made the public acquainted with the Adirondack region and named its principal mountains. In 1837 he named, described, and classified the celebrated Potsdam sandstone. Among the other rocks and divisions to which he gave a name or a place in geology are the Chazy limestone, black marble of Isle la Motte, Lorrain shales, Champlain group, Ontario group, Helderberg series, and Erie group. During the progress of this survey, also, he made the important discovery that is most closely associated with his name. In 1842 he pointed out a great system of stratified rocks under the Potsdam, which he called the Taconic System. This announcement brought upon him a storm of contradiction and ridicule, and for a time he was scientifically ostracized. Subsequent discoveries by the Canada Survey, and by Barrande, in Bohemia, however, as well as the investigations of later eminent geologists, have completely sustained him. In propounding the term Taconic System Prof. Emmons was following the instruction and views of his teacher. Prof. Amos Eaton, who promulgated his opinions regarding the age of these rocks in his lectures at Williams College from 1817 onward; and subsequently in his lectures at the Rensselaer School to the end of his life, although never having published any satisfactory account of the relations of these rocks to the formations above or below them.

Two years later Dr. Emmons described the primordial fauna, thus preceding the celebrated discoveries of Barrande, who recognized the priority of Emmons in the following courteous language:

"In comparing these dates it is clear that Dr. Emmons was the first to announce the existence of a fauna anterior to that which had been established in the Silurian System as characterizing the Lower Silurian Division, and which I have named the Second Fauna. It is, then, just to recognize the priority, and I think it all the more fitting to state it at this time, that it has not hitherto been claimed."

Prof. Emmons's Report on the Second District of the New York Geological Survey was published in 1842. In the autumn of that year his colleagues presented his name to Governor Seward as a proper person to act as custodian of the collections of the