758 



SCIENCE. 



[N. S. Vol. V. No. 124. 



possessed, and no one knows what forms 

 have disappeared and an unknown form of 

 elk or wapiti which within the memory of 

 our fathers — and of some men still living — 

 inhabited the Alleghany region from North 

 Carolina to the Adirondacks has been wiped 

 oif the face of the earth. 



C. Haet Meekiam. 



THE NATIONAL ACADEMY OF SCIENCES. 

 0>r THE VABIATION OF LATITUDE.* 



At the autumn meeting of the Academy in 

 1894 the author had presented the numerical 

 theory of the motion of the pole, synthetic- 

 ally derived from the observations from the 

 beginning of the history of the astronomy of 

 precision up to that time, in its complete 

 development, exactly as it stands to-day. 

 Since then he had been interested to com- 

 pare it with the various series of observa- 

 tions subsequently published, not only for 

 the purpose of verification and improve- 

 ment of the numerical values of the various 

 constants, but also to detect any additional 

 characteristics which these later data might 

 make apparent. These additional investi- 

 gations had individually been neither ex- 

 tensive nor important enough to call for 

 separate publication ; since their general 

 result has been merely a satisfactory con- 

 firmation of the previous deductions as to 

 the nature of the law of these motions, 

 without furnishing material improvement 

 of the numerical elements. But sufficient 

 material has thus been gradually accumu- 

 lated to make the present communication 

 of some interest. 



The new material to be here utilized con- 

 sists of the various series of observations 

 by Tallcott's method up to the middle of 

 1896, so far as published, at the following 

 European stations, named in order of longi- 

 tude : Kasan, Vienna, Prague, Berlin, Pots- 

 dam, Karlsruhe and Strassburg. In Amer- 



*Abstract of a paper presented by Dr. S. C. Chand- 

 ler. 



ica we have Doolittle's series at Bethle- 

 hem, which was brought to a close in the 

 summer of 1895. He is now carrying for- 

 ward a new series at Philadelphia of which 

 we may hope soon to see the results. Of 

 the series at Columbia University, by Eees, 

 Jacoby and Davis, begun in the spring of 

 1893 and still current, there have come to 

 hand the results for the first fourteen 

 mouths. It is an extremely fortunate cir- 

 cumstance that a portion of this series, yet 

 unreduced, will bridge the gap in Doolittle's 

 work rendered unavoidable by his removal 

 from Lehigh University to the University 

 of Pennsylvania. 



The curves of latitude variation from 

 these various series were then exhibited, 

 and compared with the numerical theory. 

 This comparison shows a fidelity of repre- 

 sentation eminently satisfactory, the differ- 

 ences between computation and observation 

 being practically within the range of errors 

 of observation. 



A determination of the elements of the 

 ellipse of the annual component of the polar 

 motion was then presented, made from the 

 newer observations, independently of the 

 older ones previously used. The resulting 

 elements are practically identical as to 

 form, size and position of this ellipse. This 

 seems to show that the axis of this elon- 

 gated vibratory motion is stationary on the 

 earth's surface, along a meridian forty-five 

 degrees east of Greenwich. This negative 

 evidence as to any apsidal motion seems to 

 be of extreme importance in its bearing on 

 the theory of the earth's rotation. 



A demonstration was then presented of 

 the fact that since 1890 the circular 428-day 

 motion has been diminishing its radius in 

 conformity to the requirements of the nu- 

 merical theory derived from the observa- 

 tions between 1825 and 1890. 



In addition to the above, a discussion 

 was presented of 645 observations of the 

 Pole Star made with the Pulkowa Vertical 



