PRESIDENTIAL ADDRESSES. 503 



an astronomical expedition to Honolulu, which 

 is within 9 of the opposite meridian to Berlin 

 (171 west from Berlin), for the purpose of 

 making a twelve months' series of observations 

 on latitude corresponding to twelve months' 

 analogous observations to be made in the Royal 

 Observatory, Berlin. Accordingly Dr. Marcusc 

 went from Berlin, and, along with Mr. Preston, 

 sent by the Coast and Geodetic Survey Depart- 

 ment of the United States, began making latitude 

 observations in Honolulu about the beginning 

 of June. In a letter from Professor Foerster, 

 received a few weeks ago, he tells me that he 

 has already received from Honolulu a first 

 instalment of several hundred determinations of 

 latitude, made during a first three months of 

 the proposed year of observations ; and that, 

 in comparing these results with the corresponding 

 results of the Berlin Observatory, he finds beyond 

 doubt that in these three months the latitude 

 increased in Berlin by one-third of a second 

 and decreased in Honolulu by almost exactly 

 the same amount. Thus, we have decisive 



