512 



SCIENCE. 



[X. S. Vol. XXI. Xo. 535. 



pendent upon habit — a radially symmetrical 

 type for those species which are erect or pen- 

 dent, and a bilaterally symmetrical tjTpe which 

 may be purely physiological due to a twisting 

 of leaves or stems or to the development of 

 dimorphism in the leaves. Many interesting 

 features were brought out with the aid of the 

 blackboard. 



Professor Underwood spoke of the number 

 of new species brought to light by recent ex- 

 ploration, and comparative study of material 

 from the American tropics, scarcely any of 

 which are common to the United States. The 

 lycopods whict in our latitude are inconspicu- 

 ous and comparatively infrequent, in the 

 tropics occasionally become weeds of large size 

 and great beauty, growing especially in high 

 altitudes, in fact most of the more interesting- 

 tropical Pteridophyta are found above the 

 5,000-foot level. Many specimens were ex- 

 hibited. Edward W. Berry, 



Secreta7-y. 



THE PHILOSOPHICAL SOCIETV OF WASHINGTOX. 



The 597th meeting was held February 18, 

 1005. 



Mr. J. W. Spencer, of the Hydrographic 

 Office, presented a number of physiographic 

 charts showing drowned river valleys and con- 

 tinental slopes in various parts of the ocean, 

 and from these argued ' On the Physiographic 

 Improbability of Land at the North Pole.' 



The continental shelf north of Eurasia is 

 now known to attain a breadth of 300-350 nau- 

 tical miles, with its border reaching to a gen- 

 eral depth of 300 feet, though there is a lower 

 platform (to 1,200-1,500 feet in Barentz Sea). 

 Beyond this edge, Nansen discovered the great 

 continental slope down to 12,000 feet. This 

 discovery precluded the occurrence of land un- 

 til islands should be found on the American 

 shelf, the position of which has not been ob- 

 served. From the occurrence of fjords reach- 

 ing from 1,200 to 4,000 feet on the eastern side 

 of the American archipelago; of others to 

 over 2,400 feet on the northern side, at a point 

 even 200 miles within the lilie of the archi- 

 pelago, and from the occurrence of deep fjords 

 on three sides of Beaumont Sea to the west, 

 it may be concluded that the continental shelf 



will be found at 50-100 miles north of the 

 present known line of islands. This would 

 correspond with the general characteristics of 

 continental shelves trenched by deep fjords 

 and valleys ofE the coast of Norway, Green- 

 land and elsewhere. Accordingly, from all 

 physiographic analogies, there is no reason to 

 expect land within 300 miles of the pole or 

 a little more. When explorers shall have 

 reached a point north of Grant Land, where 

 the depth is even less than 2,000 feet, they will 

 have established the fact that there is a sea 

 extending to the Siberian side, and scien- 

 tiiically their work will have been completed 

 in the polar region. 



Dr. Harris, of the Coast Survey, urged 

 briefly that these conclusions were irreconcil- 

 able with the conclusions he had presented 

 some months ago based on the study of tides 

 and currents in the Arctic Basin. 



Interesting memorial addresses were read, 

 one by Dr. W. H. Dall on Marcus Baker, a 

 past president of the society, the other by Mr. 

 II. G. Ogden on Adolphus Lindenkohl, late 

 the chief map draftsman of the Coast and 

 Geodetic Survey. 



Mr. Edwin Smith then spoke on ' The New 

 Transpacific Longitude Determinations.' The 

 probable error of the longitude of Manila via 

 the United States is .059 sec; the new deter- 

 mination agrees with the mean of the older 

 ones via Asia (which are not wholly cor- 

 rected for personal equation) within the error 

 stated. The results have already appeared in 

 Science. 



Mr. E. G. Fischer exliibited and described 

 the ' Rapid Recording Sounding Apparatus ' 

 of the Coast Survey. In this a weight hung 

 from a wire wound on a reel operated by hand 

 is allowed to drop to the bottom ; the wire runs 

 over a measuring wheel with printing attach- 

 ment operating on a paper strip; a time stamp 

 of ordinary tyi^e is placed to record on the 

 strip close by the wheels. When the operator 

 feels that the weight touches bottom he re- 

 verses the reel and this operation causes all 

 the printing devices to make their records; 

 these are correct to 0.2 foot and may be made 

 very rapidly. Charles K. Wead, 



Secretary. 



