TABLE OF CONTENTS. IX 



PAGE 

 JOHN J. STEVENSON. 



Notes on the Surface Geology of S. W. Virginia (March 7, 1887), 

 read by title 113 



WILLIAM E. TROWBRIDGE. 



On Sub-surface Water-supply for Cities and Towns (January 31, 



1887) 77 



Laws of Fatigue and Rest in Animal Mechanics as Applied to Boat 

 Racing (March 14, 1887) 114 



A. W. VOGDES. 



The Genera and Species of North American Carboniferous Tri- 

 lobites (March 38, 1887), read by title 122 



CHARLES B. WARRING. 



On Certain Laws of Gyrating Bodies (April 11, 1887) 131 



JOHN S. WHITE. 



The Landskibet, or Viking Skip, Discovered near Gokstad, Norway, 

 in 1880 (February 14, 1887), ivithout abstract 93 



LECTURES OF THE POPULAR LECTURE COURSE OF 



1886-1887. 



HENRY L. ABBOTT. 



Sea-Coast Defense (March 21, 1887), ivithout abstract. . 122 



WILLIAM LIBBEY. 



Recent Explorations in Alaska (January 24, 1887), without abstract. 77 



CHARLES S. MINOT. 



The Evolution of the Head (April 25, 1887), without abstract 135 



JOHN K. REES. 



The Great Telescopes of the World; their Construction, Powers, 



and Limitations (February 21, 1887) 93 



WILLIAM p. TROWBRIDGE. 



The Development of Bridge Construction, with Notices of some Re- 

 markable Historic Bridges (May 23, 1887) 148 



