24 A. D. Wackerbarth, 



on the Orbit, r the radius-vector and b the heliocentric latitude over the 

 Ecliptic of the Epoch, then 



V = 



112°. 58'. 27 



'. 6 + 79°. 3657813. t 













+ 



(63917". 



706 



- 3" 



. 61707. 



t) . sin (n 



. t + 



8 - 



- CD^ 

 / 







+ 



(6173 . 



814 



- 



. 69678. 



t) . sin 2 . 



(n . 



t + 



e — 



ro) 









(826 . 



605 



- 



. 13973. 



t) . sin 3. 



(ft. 



t + 



« — 



cti ) 





+ 





(126 . 



444 



- 



. 02847. 



t) . sin 4 



(n. 



t + 



6 — 



a>) 





+ 





(21. 



006 



- 



. 00585. 



t) . sin 5 . 



(n. 



t + 



£ — 



od) 





+ 





(2. 



463 



- 



. 00121 . 



t) . sin 6 



.(n 



t + 



£ — 



to) 





+ 





(1. 



653 



- 



. 00026. 



t ) . sin 7 



.(n 



t + 



t — 



») 





+ 





. 



257 



. sin 



8 . (n.t 



+ £ — as) 













r = 



3 



. 0711461 



- 



000 003 



768. t 















(0 



. 4220541 



- 



000 023 



586.0 • 



cos 



(n 



t + 



6 — 



/ 





(0 



. 0325417 



- 



. 000 003 648 . t) . cos 2 



<YI 

 \ n 



l T 



£ — 



CO ) 





(0 



. 0037716 



- 0. 



000 000 



634 . t) . cos 3 



(ft 



. t + 



£ — 



CO) 





(0 



. 0005193 



- 0. 



000 000 



116 . t) . cos 4 



(ft 



. t + 



? — 



co) 





(0 



. 0000782 



- 0. 



000 000 



021 . t) . cos 5 



(n 



t + 



e — 



Of)) 





(0 



. 0000174 



- 0. 



000 000 



004 . t) . cos 6 . 



(ft. 



t + 



£ — 











. 0000088 



cos 



7 . (n.t + e — co) 



















. 0000002 



cos 



8 . (n . t + e — «j 













sin £ = (0 . 1214137 . - . 000 001 862 t) sin (i< - 5>) . 



The time t is reckoned in Julian years of 365| days each from the 

 noon of the l sl of Jan. 1856, (Greenwich). Should t be expressed in days, 

 one has only to substitute 782". 250 instead of 79°. 3657813, to give that 

 value also to n in the arguments, and to divide the numbers multiplied by t, 

 which express the secular variation of the coefficients, by 365|, or in other 



words, to substitute — — for t throughout the formula. 

 365.25 & 



Corrigenda. 



Page 3. Line 4. For Chiloraetres read Chiliometres 



Fage 3. Add as Foot-note 



The opposition of 1866, occurring in the month of May, when the planet has a South declination of 

 above 27°, is not likely to furnish, at least to observers residing in Europe, any very favourable 

 opportunities of increasing our knovvlegde of this planet. 



Page 13. Line 5. After Longitude ad l as re/erred to the Fixt Ecliptic. 



Page 16. Line 7. For siu read sin 



