AMOS EATON. I! 5 



ceum, from Illinois, of gypsum and secondary sandstone, and 

 informed me that the latter overlaid the former in regular 

 structure. Myron Holly and others have given me similar 

 specimens, which they represent as being similarly situated, 

 from localities in the western part of this State. This secondary 

 sandstone is sometimes more or less calcareous. I believe it 

 is used for a cement by the canal company, which hardens 

 under water. Will you do me the favour to settle this question ? 

 On your way to Detroit you may perhaps, without material in* 

 convenience, collect facts of importance to me in reference to 

 secondary and alluvial formations. Anything transmitted to 

 me by the middle of April on these subjects will be in season, 

 because I shall not have printed all the transition part before 

 that time. Have you any knowledge of the strata consti- 

 tuting the Rocky Mountains ? Is it primitive, or is it gray- 

 wacke, like Catskill Mountains ? I have said in a note that 

 after you and Dr. E. James set foot upon it we shall no 

 longer be ignorant of it. I intend to kindle a blaze of 

 geological zeal before you return. I have adapted the style 

 of my index to the capacity of ladies, plough-joggers, and 

 mechanics." 



Prof. Eaton also delivered lectures at Lenox Academy and 

 the Medical College at Castleton, Vt., where he was appointed 

 Professor of Natural History in 1820. He gave lectures and 

 practical instructions in Troy, and thus laid the foundation for 

 the establishment there, as a direct result of his work, of the 

 Lyceum of Natural History ; and it is said that in the fall of 

 1818 Troy could boast of a more extensive collection of 

 American geological specimens than could be found at any 

 other literary institution in this country. The geological and 

 agricultural survey of Albany and Rensselaer Counties, made 

 in 1820 and 1821, by Prof. Eaton and Drs. T. Romeyn and 

 Lewis C. Beck, at the expense of the Hon. Stephen Van Rens- 

 selaer, is believed to have been the beginning of such surveys in 

 this country, and was described by Prof. Silliman, in his Jour- 

 nal, as a novel attempt. Next was a geological survey by 

 Prof. Eaton, also at the instance of Mr. Van Rensselaer, of 

 the district adjoining the Erie Canal, the result of which was 

 published in 1824, in a report of one hundred and sixty pages, 

 with a profile section of rock formations, from the Atlantic 

 Ocean, across Massachusetts and New York, to Lake Erie. 



