IN THE ARCTIC SEAS. 



29 



The radial correction, obtained graphically, is as follows: — 



Reduction to centre . 



k' . 



k'-i-b' 



k'—b' 



d' . . . . 



a' 4-p=a . 



m — n 



Reduced to time of true 6 



t . . . . 



Time of true 6 m Van Rensselaer mean time 5'' 0'' 32™ 37^0 — 1.01 dB 



32 44.6 — 0.5G dB 



32 23.1 —0.56 dB 



Hence longitude of Van Rensselaer from immersion 4'> 43" 27^6 



(75= + 7.1 



emersion (C) 4 43 16.9 

 {R) 4 43 38.4 



V- 



7^0 



Resulting longitude 



4 43 27.6 



Longitude from the Observations of the Occultation of Mars. 

 February 13, 1854. 

 Immersion, first contact .... 20'' 22™ 10^8 mean time. 17** 59™ 04''. 4 sid. time. 



second " .... 20 23 06.6 " 18 00 00.4 



Emersion, last " .... 20 53 17.3 " 18 30 IG.l 



Approx. Greenwich mean time, phase (1) 

 " (2) 

 " (3) 



14d 



] 05 42.8 

 1 06 38.6 

 1 36 49.3 



From the Greenwich Nautical Almanac, as corrected from the Greenwich observations : — 



At immersion (1), a € . .11'' 02™ 21^.84 



(2) . . 11 02 23.65 



At emersion (3) . . 11 03 24.21 



(Correction to Nautical Almanac — 0''.28 ) 

 At immersion (1), « C . . +11° 34' 05".8 



" (2) . . 11 33 54.4 



At emersion (3) . . 11 27 32.9 



(Correction to Nautical Almanac +0".4.) 

 At immersion (1), horizontal paral. <L 56' 12". 6 



(2) ... 56 12.7 



At emersion (3) . . .56 13.2 



(Adams' correction +0 ".5.) 

 At immersion (1), seniidiaraeter C . 15' 19". 3 



(2) ... 15 19.3 



At emersion (3) . . . 15 19.4 



(Correction to Nautical Almanac — 0".3 

 + Oudeman's correction — l".l.) 



At immersion (1), a. ^ . . 11'' 02™ 32^24 

 (2) . . 11 02 32.20 



At emersion (3) . . 11 02 30.65 



(Correction to Nautical Almanac +1'.56.) 



At immersion (1), i g . . +10° 47' 54". 7 

 (2) . . 10 47 55.0 



At emersion (3) . . 10 48 05.5 



(Correction to Nautical Almanac — 17". 4.) 



Horizontal paralla.x J* . . 12 ".3 



Semidiameter cf . . G". 4 + 1". 8 = 8". 2 



