PRESIDENTIAL ADDRESSES. 505 



would alter the latitude of a place 90 from it 

 in longitude by an amount equal to the angular 

 change of the position of the axis. Thus two 

 stations in meridians differing by 90 would 

 theoretically suffice, by observations of latitude, 

 to determine the changes in the position of the 

 instantaneous axis ; but differential results, such 

 as those already obtained between Berlin and 

 Honolulu, differing by approximately 180 in 

 longitude, are necessary for eliminating errors of 

 observation sufficiently to give satisfactory and 

 useful results. It is to be hoped that England, 

 and all other great nations in which science is 

 cultivated, will co-operate with the International 

 Geodetic Union in this important work. 



Among the most interesting scientific events 

 of the past year was the celebration of the 

 hundredth anniversary of the birth of Faraday 

 by the two Faraday Lectures in the Royal Institu- 

 tion last June. In the first of these, which was 

 delivered by Lord Rayleigh, under the presidency 

 of the Prince of Wales, an old pupil of Faraday's 

 and now Vice-Patron of the Royal Institution, 



