466 



SCIENCE. 



[N. S. Vol. VIII. No. 197, 



yond the greatest extent of the ice-sheet, 

 and of the Missouri River almost entirely 

 within the limits of the ice, was due to the 

 different angles which these streams made 

 with the ice-front, and to their different 

 gradients. In the Ohio basin the water 

 was forced over distant cols ; but in the 

 Missouri basin it was drained southeast- 

 ward along the ice-front, thus wearing back 

 the ice at the time of final recession before 

 the establishment of the channel by erosion. 



14. Classification of Coastal Forms. By F. 

 P. Gulliver, Southboro, Mass. A scheme 

 is proposed in this paper for the classifica- 

 tion of the various forms of the coast ac- 

 cording to their stage of development. 

 Two markedly different classes of initial 

 forms are recognized, those following ele- 

 vation of the land and those following 

 depression. Each class is seen to have 

 characteristic forms at various stages of its 

 development, and the writer urges others to 

 think of all the forms on the coast or along 

 the shore as in a certain stage of their life- 

 history. This will further suggest the form 

 from which any given example has come 

 and toward which it tends to develop. 



15. Dissection of the Ural Mountains. By 

 P. P. GtTLLivEE. The Urals are seen to be 

 pretty thoroughly planed, so that the sum- 

 mits of the many ridges rise to nearly the 

 same elevation, except a few commanding 

 peaks which are found to consist of quartz- 

 ite or other rock more resistant than the 

 surrounding beds. The summit-level plane 

 descends gradually to the west until it 

 merges into the upland levels of the great 

 plain of Russia, while on the east in several 

 places there is a rather steep fall-off to the 

 Siberian plain, though in other places the 

 plane of the summits merges into that of 

 the great Tertiary deposits of northwestern 

 Asia. The stages of dissection in various 

 parts of the Ural Mountains, and the grade- 

 planes of different streams, are compared, 

 the result of such comparison being that 



there seem to be three epicycles or divisions- 

 of the present cycle of erosion. 



16. Note on Monadnoch. By F. P. Gulli- 

 ver. The relation of Monadnock to the New 

 England upland was considered, and the 

 valleys in the vicinity of this mountain 

 were described. The elevations of two 

 former stream grades have recently been 

 determined in this region. 



17. Spacing of Rivers with Reference to the 

 Hypothesis of Baseleveling . By Professor N". S. 

 Shaler, Cambridge, Mass. (Read by title. ) 



18. The Continental Divide in Nicaragua. 

 By C. WiLLAED Hayes, Washington, D. C. 

 The comparatively short streams, with steep 

 gradients, descending to the Pacific, have 

 in numerous instances increased their drain- 

 age basins by capture of the headwaters of 

 streams flowing eastward to Lake Nicaragua 

 and the Caribbean Sea. In this way the 

 water divide on the surveyed line for the 

 Nicaragua Canal has been removed a con- 

 siderable distance eastward, being now at 

 a much lower altitude than the original 

 mountainous watershed. 



The following papers were presented in 

 the session of the National Geographic 

 Society :* 



1 . The Venezuela- British- Guiana Boundary 

 Dispute. By Dr. Marcus Baker, Washing- 

 ton, D. C. 



2. Considerations Governing Recent Move- 

 ments of Population. By John Hyde, Wash- 

 ington, D. C. 



3. Some new Lines of Work in Government 

 Forestry. By Gifford Pinchot, Washing- 

 ton, D. C. 



4. The Development of the United States. 

 By W J McGee, Washington, D. C. 



5. Atlantic Estuarine Tides. By M. S. W. 

 Jefferson. 



6. Tlie Forestry Conditions of Washington 

 State. By Henry Gannett, Washington, 

 D. C. 



* See the account by W J M in the issue of Science 

 for Septemher 16th. 



