(Vol. IX. Part /.—p. 234J 

 ■cum-mcridian Observation, made at Makerstown, 10th February 1820, in order to determine His Latitude, and nidi « View of 



Table II. 



!" the Accuracy Iliac may lie obtained liv tliat Mode of obscrvin 



;.— Lonciiroi! in Timo west of Greenwich nearly 10' 4". Quicksilver Horizon, covered by one of Troughton's 



Noon by Chronometer. 



Time from 2 Sing a \ P Observe 



Noon. Sine 1" Angles 



67.90 

 89.17 

 21.38 

 11.15 



39 IS 00 

 13 20 

 13 20 

 13 25 

 13 27 

 13 30 

 13 30 



Altitudes corrected 

 for error of instru- 

 ment — 45" 



17 35' 37*5 



35 52.5 



36 17.5 

 36 20.0 

 36 21.0 

 36 22.5 

 36 22.5 



Logy 



: H Co-sine D 



34 07.2 

 34 11.3 

 34 15.0 

 34 16.9 



Sine (H+ 11) 

 Formula for Log-.A 



: 70 10 11 Ar. Co-sine 0.0265; 

 Log. / = 9.76460 



O's declination nt noon by Ephemeris, - = 14 35 48 



10' 4" west of Greenwich, - - — 8.7 



Declination corrected for dilference of meridians, 14 35 39.3 



For tile refraction 



8 03 



9 06 

 9 59 



u.os 



7.99 



13 2-5 





36 20.0 



34 16.6 











Barometer, 



29.52 = 



0.7495 = 9.9938 









. 2.54 



16.51 



13 05 





30 10.0 



34 22.5 











Thermometer, 



46 .3 = 



8.0 = O.0033 









3.44 



27.37 



12 50 





36 2.5 



34 24.3 











Zenit 



1 distance, 



.70 



2.2009 









11 42 



4.37 



41.85 



12 45 





36 0.0 



34 19.2 

















23.6 94 









12 24 



5.19 



55.49 



12 30 





85 52.5 



34 19.2 

























13 06 



6.01 



71.07 



12 00 





35 37.5 



34 25.8 

















2.2074 









14 05 



7.00 



96.20 



11 45 





35 30.0 



34 19.5 















Refraction, 



— 161.2 









14 54 



7.49 



119.96 



11 10 





35 12.5 



34 23.8 















Parallax, 



+ 8.4 









16 16 



9.11 



165.57 



10 20 





34 47.6 



34 23.3 

























17 18 



10.13 



204.92 



9 50 





34 32.5 



34 16.3 















152.8 



— 2 32.8 



O's semi-diameter, + 16 13.8 











— 55 34 18.6 































Semi-diameter 4- Parallax — Refraction = 13 41.0 









Numbers corresponding to horary angles, 

 Logarithms, 



67.06 



39.17 



21.38 



11.15 



4.32 



0.16 



1.83 



7.98 



16.61 ' 



27.37 



41.86 



55.49 



71.07 



96.20 



119.96 



165.57 



£04.92 



1.83225 



1,59295 



1.33001 



1.04727 



0.03548 



9.20412 



0.20245. 



0.90255 



1.21775 



1.43727 



1.02170 



1.74421 



1.85169 



1.98318 



2.07904 



2.21898 



2.31158 



Constant factor, or IjOg.Jl 



9.76160 



9.76460 



9.76460 



9.70460 



9.76460 



9.76460 



9.76460 



9.76460 



9.76460 



9.70400 



9.70460 



9.70460 



9.76460 



9.76460 



9.76460 



9.76460 



9.76460 



Constant factor -(- Log. of numbers, 



1.69085. 



1.35755 



1.09161 



0.81187 



0.40008 



8.96872 



0.02705 



0.66715 



0.9S235 



1.201S7 



1.38630 



1.50881 



1.01029 



1.74778 



1.84364 



1.98358 



2.07618 



Corrections, 



+ 39.5 



22.8 



1S.4 



6.5 



2.5 



0.1 



1.1 



4.7 



9.6 



16.9 



24.3 



32.3 



41.3 



55.9 



C9.8 



90.3 



119.2 



O's declination corrected for different meridians 



D = 11 35 39.3 



14 36 39.3 



14 35 35.3 



14 35 39.3 



14 35 39.3 



14 35 39.3 



14 35 39.3 14 35 39.3 



14 35 39.3 



14 35 39.3 



14 35 39.3 



14 35 39.3 



14 35 39.3 



14 35 39.3 14 35 39.3 



14 35 39.3 



14 85 39.3 



Corrections for horary angles, 



+ 4.7 

 + 14 35 44.0 



+ 3.6 



+ 2.6 



+ 1.9 



+ 1.2 



+ 0.2 



— 0.8 - 



1.6 



— 2 - 4 



— 3.0 



38 . 



4.3 



— 4.9 



— 5.7 - 



6.4 



— 7.1 



8.3 









D corrected, 



14 35 42.9 



14 35 413 



14 35 41.2 



14 35 40.5 



14 35 39.5 



14 35 38.5 U 35 37.7 



14 35 30.9 



14 35 30.3 



14 35 35.5 



14 35 85.0 



14 35 34.4 



14 35 33.6 14 35 32.9 



14 35 31,9 



14 35 31.0 



Altitudes corrected for error of instrument, 



+ 19 35 37.5 



35.52.5 



36 17.5 



36 20.0 



36 21.0 



36 22.5 



3G 22.5 



36 20.0 



36 10.0 



36 2.5, 



36 0.0 



35 52.5 



35 37.6 



35 30.0 



35 12.5 



34 47.5 



34 82.6 



Semwliiuneter + Parallax — Refraction 

 Reduction to noon. 



+ 13 41.0 



+ site 



13 41.0 

 22.3 



13 41.0 



12.4, 



13 41.0 

 6.5 



13 41.0 

 . 2.5. 



13 41.0 

 0.1 



13 41.0 

 1.1 



13 41.0 



4.7 



13 41.0 

 9.6 



13 41.0 

 15.9 



13 41.0 

 24.3 



13 41.0 

 32.8 



13 410 

 41.3 



13 41.0 

 55.9 



13 41.0 

 1 9.8 



13 41.0 

 1 86.3 



13 41.0 

 1 69.2 



Co-latitudes, or height of cqualnr, 



ill 25 12.0 



25 39.2 



25 528 



25 48.7 



25 15.0 



25 43.1 



25 43.1 



2.5 43.4 



25 37.5 



25 35.7 



25 40.8 



25 40.8 



25 34.2 



25 40.5 



25 36.2 



26 36.7 



25 43.7 



Latitudes, 



55 34 18.0 



34 20.S 



34 072 



34 11.3 



34 15.0 



84 16.9 



34 16.9 



34 16.0 



34 32.5 



34 24.3 



34 19.2 



34 19.2 



34 25.8 



34 19.5 



34 23.8 



34 23.3 



34 16.3 













10th of February, mean of 17 Latitudes, 



55° 34' 18.6 































9th of February, - 17 Latitudes, 



Mean, 



55 34 14.2 



Lat. of Mnkcrstown. 



















55 34 16.4 





North nl" the Equtitoi 



