O NEW YORK STATE MUSEUM 



thousands of people during the summer season. Of late years 

 Lake Placid has enjoyed considerable popularity as a winter resort. 

 Thirty-five or forty years ago there was great activity at East, 

 Middle and West Kilns where charcoal was made for use in iron 

 furnaces at Black Brook a few miles to the east. 



In 1842 Prof. E. Emmons published his Survey of the Second 

 Geological District, including Essex county. This report, how- 

 ever, contains almost nothing on the geology of the Lake Placid 

 region. 



To Prof. J. E. Kemp belongs the credit of first having done 

 extensive field work which Has resulted in solving many important 

 problems in the geology of Essex county. He published reports, 

 based upon reconnaissance field work, on the geology of the county 

 in 1893 and 1895. These reports contain important data pertaining 

 to the geology of that portion of the Lake Placid quadrangle which 

 lies in Essex county. Based upon this reconnaissance work, Pro- 

 fessor Kemp also published a report, accompanied by a geologic 

 map, on the vicinity of Lake Placid. At one time it was planned 

 that Professor Kemp and the writer should prepare- a joint report 

 and map based upon a detailed study of the Lake Placid quad- 

 rangle. Soon after entering the field in 191 5, however. Professor 

 Kemp was obliged, on account of health, to abandon the work. He 

 generously allowed the use of certain data on his field map. The 

 writer gratefully acknowledges his indebtedness to Professor Kemp. 



Prof. H. P. Gushing, in his Preliminary Report on the Geology 

 of Franklin Gounty, makes a number of references to the rock 

 formations in the vicinity of Franklin Falls, in the northwestern 

 part of the quadrangle. Professor Gushing also briefly refers to 

 some of the formations in that part of the quadrangle which lies 

 in Glinton county in his Report on the Geology of Glinton Gounty. 



Mr H. L. Ailing, who contributes the chapter on the Pleistocene 

 of the quadrangle in this bulletin, has kindly furnished data, more 

 especially the location of several diabase dikes and Grenville lime- 

 stone outcrops, and the use of some thin sections of rocks. 



Mr Herbert Insley, a former student in the writer's classes, 

 assisted in the survey around Keene and on the rough Sentinel 

 range. For this service the writer is sincerely grateful. 



Prof. D. W. Johnson has kindly permitted the use of two photo- 

 graphs. 



Following are the principal publications which bear more or less 

 upon the geology of the quadrangle: 



