14 



students, all from the Senior Class. Yarions special subjects of 

 study were followed ; theses on those taken by Mr. Ward, " The 

 Sea-breeze," and by Mr. Curry, " The Theory of Tornadoes," will 

 be shortly published. The students from this class and two from 

 the advanced class in geological field«work accompanied the in- 

 structor in an excursion during the April recess across Northern 

 New Jersey and into Central Pennsylvania, with the object of 

 examining the traces of ancient base-levels in that region, and 

 thus learning something of the development of its river valleys. 

 The results of this study are now published in the National 

 Geographic Magazine. 



Mr. Davis's other work of instruction in the year was in 

 two geological courses, on which Professor Shaler has reported. 

 During the summer, two weeks were spent at Madison, Wis- 

 consin, taking part in the summer school for teachers opened 

 there by the State University ; fourteen lectures on Physical 

 Geography were here given to a class of about fifty members. 

 Later in the vacation, the Harvard Summer School of Geol- 

 ogy was in his charge at Catskill, New York, and at Meriden, 

 Connecticut. 



The materials for use in the Geographical Laboratory have 

 been increased during the year by the purchase of a set of relief 

 maps, copies of those designed and in part made by Mr. Davis 

 two years ago for the Teachers' School of Science of the Boston 

 Society of Natural History. These have .been found of much 

 value in class instruction. There have also been purchased an 

 excellent terrestrial globe ; a set of the monthly volumes of tri- 

 daily weather maps issued by the Signal Service, these being 

 particularly for the use of students in the elementary course ; 

 Haardt's and other maps of the Alps ; Kiepert's physical maps 

 of the various countries of Europe ; and several climatological 

 maps. The Laboratory has also received as a gift from the Penn- 

 sylvania Railroad Company a valuable set of large photographs 

 illustrating the scenery along its lines. 



During the winter, Mr. C. L. Whittle, Assistant, United States 

 Geological Survey, carried on, under Mr. Davis's direction, an 

 investigation of the characteristics of the intrusive and extrusive 

 trap sheets of the Connecticut Valley, the results of which are 

 now ready for publication in the. Museum Bulletin. Mr. Davis's 

 publications during the year were as follows : — 



