OBSERVATIONS. 



clix 



Interval of Declination-threads in the Athens Meridian-Circle. 



The thread A has been taken as the standard, and all the circle-readings corresponding to 

 observations with B, are reduced by subtracting the assumed distance between the two threads. 

 The observations on the successive days hardly permit any trustworthy inferences regarding the 

 fluctuations of the zenith-point, but show the nonexistence of any progressive change. They 

 are here given in full detail in the table of circle-readings. 



In this table all the observations of each star are grouped together ; the columns headed 

 Level and Refraction being taken directly from Professor Bouris's paper. The apparent decli- 

 nations of the stars observed have been deduced from the list of mean places and constants for 

 reduction to the apparent equinox, given at the close of the preceding division of this article. 

 The ninth column, headed Zero of circle, gives the declination corresponding to the circle- 

 reading 0, or, in other words, the distance of the equator-point for the thread A from the zero 

 of graduation, as indicated by each observation. 



