of Bessel's Astronomical Observations. 



175 



Lower Passage. — Circle East. 



The deviation of these determinations of* the altitude of the 

 pole from the one obtained above by reversing the instru- 

 ment, proves a sensible flexure. Supposing it to be of such a 

 nature thai it might be counteracted in every position of the 

 telescope with regard to the horizon, by applying invariable 



counter- 



