832 



SCIENCE. 



[N. S. Vol. XVII. No. 438. 



tutions of this kind generally confine their 

 activities to the professional and scholastic 

 classes, but here is one that is bringing its 

 culture and its wealth of knowledge, based 

 on careful research, to the help of the common 

 people in their practical, every-day work." 

 E. H. Thurston. 



THE INTERNATIONAL GEODETIC ASSO- 

 CIATIONS 



The systematic reduction of the 52° parallel 

 survey was published by the Central Bureau 

 of the International Association under the 

 title ' Lotabweichungen, Heft II.' The pub- 

 lication of the third part, which will contain 

 the deflections along the northern geodetic 

 lines of the 52° parallel survey, will be at- 

 tempted this year. 



Owing to the resignation of Dr. Schumann, 

 who accepted the position of professor of 

 geodesy, Fischer High School, the investiga- 

 tion of the curvatures of the meridians and 

 parallels of the ' geoid ' could be but little 

 advanced. Still, preparations for the compu- 

 tation of the triangulation through Prance, 

 Spain and Algiers are in progress, and it is 

 hoped that the final computations will be com- 

 pleted during the coming year. 



Voluntary contributions of observations for 

 variations of latitude during the year, from 

 which to determine the motion of the earth's 

 axis of rotation within its body, were received 

 from only four observatories, namely, the ob- 

 servatories of Tokyo, Heidelberg, Leyden and 

 Philadelphia.. Unfortunately, the data thus 

 furnished proved insufficient for an inde- 

 pendent determination of the pole's motion. 

 Htilizing these contributions, the results were 

 compared with the motion of the pole as de- 

 duced from the series of special observations 

 executed by the International Latitude Ser- 

 vice, and it is gratifying to note that the com- 

 parisons proved the results to be satisfactory. 



In this connection it remains to call atten- 

 tion to publication No. 6, of the Central 



* Abstract of Professor Helmert's report on the 

 activities of the Central Bureau of the Inter- 

 national Geodetic Association during the year 

 1902, together with the proposed plan of work 

 for 1903. 



Bureau, entitled ' Ergebnisse der Polhohen- 

 bestimungen in Berlin ' during the years of 

 1889, 1890 and 1891, by Dr. Adolf Marcuse. 

 The work of the International Latitude Ser- 

 vice made satisfactory progress during the 

 year. Star-pairs were observed as follows : 



No. of Pairs 

 Stations. Observed. Observers. 



1. M\zusawa 1,.577 .Kimura and Nakano. 



2. Tschardjui 1,564 Medzwietsky. 



3. Carloforte 3,386 Ciscato and Bianchi. 



4. Gaithersburg 1,822 Davis. 



.5. Cincinnati 1,425 Porter. 



6. Ukiah 2,014 Schlesinger. 



The reduction of these observations was 

 made immediately upon the receipt of the 

 records by mail. In addition to these sys- 

 tematic computations, the Central Bureau 

 also undertook the reduction of the mean dec- 

 linations. The mean declinations were de- 

 rived from Cohns' catalogue. 



A list of the apparent declinations of the 

 several stars thus observed, for the epoch of 

 Greenwich culmination for the period No- 

 vember 2, 1902, to November 1, 1903, was pre- 

 pared, and a copy sent to the observers for the 

 purpose of enabling them to test and control 

 their respective works by their own computa- 

 tions. 



An abstract covering the most important re- 

 sults of this work is given by Dr. Albrecht 

 in his article in No. 3808 of the Astronoviische 

 Nachrichten, entitled ' Resultate" des inter- 

 nationalen Breitendienstes ' for 1899.9-1902.0. 



In this article Dr. Albrect calls atten- 

 tion to the fact that the motion of the earth's 

 pole could no longer be satisfactorily repre- 

 sented by the expression : 



A<p-{-v^x cos A + 3/ sin A, 

 but that according to the suggestion of Pro- 

 fessor Kimura in Astrom. Nachr., No. 3783, 

 an expression of the form 



&<!> -{-v = x cos A + ?/sin ^ -j- z 

 would have to be used instead. That is to 

 say, the complete expression for the variation 

 of latitude required an additional yearly term 

 (z), wholly independent of the geographical 

 longitude of the place of observation. 



Determination of the Acceleration of Grav- 



