Mr. Ivory on the Theory of the AstronomicalHefr actions, 97 







Reflections 





Zenith 

 dist. 









New Table. 



Tab. Reg. 



Conn, des Temps. 



o 

 10 



10-30 



10-30 



// 

 10-30 



20 



21-26 



21-26 



21-26 



30 



33-72 



33-72 



33-72 



40 



48-99 



48-99 



48-99 



45 



58-36 



58-36 



58-36 



50 



69-52 



69-52 



69-52 



55 



83-25 



83-24 



83-25 



60 



100-85 



100-85 



100-86 



65 



124-65 



124-62 



124-65 



70 



159-16 



159-11 



159-22 



75 



214-70 



214-58 



214-83 



80 



320-19 



319-88 



320-63 



81 



353-79 



353-38 



354-33 



82 



394-68 



394-20 



395-37 



83 



445-42 



444-86 



445-87 



84 



509-86 



509-23 



511-22 



85 . 



593-96 



593-38 



595-80 



85i 



646-21 



647-10 



648-34 



86 



707-43 



707-15 



710-07 



861 



779-92 



777-36 



783-07 



87 



866-76 



864-59 



870-37 



87i 



971-93 



972-21 



975-89 



88 



1101-35 



1101-40 



1105-1 



881 



1262-6 



1265-5 



1265-0 



89" 



1466-8 



1481-8 



1464-9 



891 



1729-5,; 



1764-9 



1716-4 



From this view it appears that the three tables agree within 

 less than 1" as far as 80° from the zenith; the new table 

 is in accordance with Bessel's, with slight discrepancies, to 

 88° or 881° from the zenith ; from 80° to 88° of zenith di« 

 stance the numbers in the French table exceed those in 

 Bessel's, the excess being 2" at 84°, and 4" at 88°. But 

 when the distance from the zenith is greater than 80°, the 

 accuracy of the French table is questionable, both on account 

 of the hypothetical law of the densities, and because the quan- 

 tity assumed for the horizontal refraction is uncertain. 



A few examples are subjoined, as well for explaining the 

 use of the new table as for affording some indications of its 

 accuracy at low altitudes. The two first instances are taken 

 from the Tables Astronomiques, and are likewise published 

 yearly in the Conn, des Temps. 



Phil. Macy. S. 3. Vol. 16. No. 101. Feb. 1840. H 



