582 



SCIENCE. 



[N. S. Vol. XIX. No. 484. 



three nortliern continents are connected 

 throughout the Oligoeene, Miocene, Pliocene 

 and Pleistocene, Africa being joined to them 

 by the Miocene, South America by the 

 Pliocene epoch. The Pleistocene map shows 

 especially the simultaneous glaciation of both 

 northern and southern regions, modified in the 

 north by sinking of the old Arctic continent 

 beneath the sea level. 



The supposed ancient continents of Lemuria, 

 Atlantis, the Brazil-African land bridge, etc., 

 are regarded either as proposed on insufficient 

 data or as being outside the limits of this 

 series. 



In general it has been found possible to con- 

 sider the true ocean basins (limited by the 

 1,000-foot contour) as permanent throughout 

 Tertiary time. The union of Antarctica with 

 Australia and South America is an exception 

 to this rule, but is based on a large amount of 

 evidence. It appears probable also that the 

 disturbed belt which stretches through cen- 

 tral Europe to south-central Asia, and ends 

 perhaps in the East Indian islands, has been, 

 in part, raised from abyssal depths to an 

 equally stupendous height above the sea, since 

 the beginning of the Tertiary. 



Discussion. — Professor Osbom emphasized 

 the value of these maps as expressing working 

 hypotheses for the use of students of verte- 

 brate paleontology. 



Dr. Julien called attention to the evidences 

 of glaciation in South Africa as having a 

 bearing upon the question of a previous ex- 

 istence of land masses farther south. 



Edmund Otis Hovet, 



Secretary. 



ASTRONOMY, PHYSICS AND CHEMISTRY. 



The regular meeting of the section was held 

 on February 1 at the American Museum of 

 Natural History. 



The first paper of the evening was a bio- 

 graphical sketch of the late Dr. H. Carrington 

 Bolton by Dr. D. S. Martin, which was read 

 by Professor Crampton, the recording secre- 

 tary of the academy, in the absence of Dr. 

 Martin. The section then passed a resolution 

 to the effect that Dr. Martin's address should 

 be published in the Annals of the academy, 



together with a bibliography of Dr. Bolton'a 

 papers. 



The second paper was entitled ' Eesearches 

 as to the Identity of Lexell's Lost Comet of 

 1770 with the Periodic Comet of 1889, 1896 

 and 1903,' and was read by Professor Charles 

 Lane Poor. This paper gave the result of a 

 new investigation of the motion of the peri- 

 odic comet of 1889, 1896 and 1903 (Brooks), 

 dealing especially with the great changes in 

 its orbit caused by the close approach to 

 Jupiter in 1886. The comet has now been 

 seen at three returns to perihelion and the 

 many observations made allow of a most ac- 

 curate determination of the present orbit on 

 which to base the investigation. Attention 

 was called to the supposed identity of this 

 body with the lost comet of Lexell, 1770, which 

 disappeared after passing close to Jupiter in 

 1779, and this question was discussed at 

 length. 



The next paper, entitled ' The Year's Work 

 with Radium,' was read by Dr. George B. 

 Pegram, and was the second of the series on 

 ' Recent Progress in Physical Science.' Dr. 

 Pegram gave a review of the most important 

 experimental and theoretical advances made 

 during the past year in the knowledge of 

 radio-activity; especially the work of Ruther- 

 ford and Soddy in formulating the atomic 

 disintegration theory of radio-active change, 

 the discovery of Curie in regard to the heat- 

 ing effect of radium, and the experiments of 

 Ramsay and Soddy bearing on the question 

 of the continuous production of helium in 

 radium compounds. An apparatus was ex- 

 hibited like that of Mr. Strutt, to show by the 

 alternate charging and discharging of an elec- 

 troscope the production of electric charges by 

 radium. The charging of the gold leaf in the 

 apparatus shown by Dr. Pegram took place in 

 about one minute. 



The next meeting of the Section of Astron- 

 omy, Physics and Chemistry was held on 

 March 7 and was devoted to an address by 

 Dr. S. A. Mitchell under the title 'Recent 

 Progress in Astronomy,' the subject being 

 ' The Results of the Observations of the Last 

 Solar Eclipse.' Dr. Mitchell gave an inter- 

 esting resume of the results obtained by the 



