ZENITH. 



Table for converting the Divifions (hewn on the Micro- 

 meter Head into Seconds, the Space fubtended by Five 

 Minutes on the Limb being found equal to Five Revolu- 

 tions and Forty-five Divifions, as deduced from the 

 Meafurement of the total Arcs. 



Table for fupplying the 

 ferved Zenith-Diftance 



Expanfion or Contraftion of the SeAorial Tube' by O 

 Degree of Heat. ' 



neceflary Correaion to the ob- 

 of a Star, on account of the 



Observations made by Captain William Mudge on the Zenith-Diftances oi y Draconis, with Ramfden's 



Zenith-Seftor, at different Places. ^ 



Table I Greenwich Obfervatory, 1802. Point on the Limb 0° o' N. 



Vol. XXXIX. 



