Considerations on the Problem of Latitude Variation. 3! 



my standpoint, this is to be looked upon as a natural and necessary 

 consequence. 



The notion that tlie level is not suited to the most delicate 

 measurements is not novel. Already as earty as in the year 1893, E. 

 von Rebeur-Paschwitz^^ insisted on the inadequacy of the spirit level 

 to meet the disturbance in precise astronomical measurements from 

 pulsatory or microseismic movements of the ground. Also G. H. 

 Darwin is said to have declared to the same effect, — ''I venture 

 to predict that at some future time practical astronomers will no 

 longer Ije content to eliminate variations of level merely by taking 

 means of results, but Avill regard corrections derived from a special 

 instrument as necessary to each astronomical observation." 



Altliough the motive of my idea is not strictly the same as 

 that of these authorities, our resulting conceptions are convergent, 

 and I am pleased to conclude my paper with the expectation that 

 Darwin's prediction will be promptly actualized in order to meet 

 the degree of accuracy required in up-to-date astronomical ob- 

 servation. 



Lastly, the writer desires to express his sincere thanks to the 

 several astronomers and observers referred to above, by whose 

 efforts and information he has been enabled to accomplish this 

 work. 



The Tokyo Astronomical Observatory, September 1915. 



Published Nov. 30th, 1915. 



1) 4stronomische Nachrichten, Nr. 3177. 



