{ "id": "a28de53dde39d7c6c5a4e6e6db8c6886144bb8a8", "text": "XLIV Variation of the Compass, as observed on board the Endeavour Bark, in a Voyage round the World. Communicated by Lieut. James Cook, Commander of the said Bark.\n\nN. B. THE day of the month is noted according to the nautical account, which therefore in all the observations noted P. M. is one day forwarder than the civil account. The latitude in is deduced from the last preceding meridian altitude of the sun; and the longitude in is corrected by the last observations of the distances of the moon from the sun and stars.\n\n| Time | Lat. in | Long. in | Variation | Remarks |\n|------------|---------|----------|-----------|---------|\n| | North | West | How found | Means |\n| 1768 | | | | |\n| August 8 | English Channel | C. Finestre S. by ½ | pr. Azimuths | 23° 6' W. |\n| September 5 | W. 6 leagues | | pr. Azimuths | 18° 42' |\n| 6 | 42° 9' 50\" W. | | pr. Azimuths | 21° 40' |\n| 7 | 40° 29' 10\" 11' | | pr. Azimuths | 21° 4' |\n| 9 | 37° 4' 11\" 34' | | pr. Azimuths | 19° 50' |\n| P. M. } | 36° 46' 11\" 58' | | pr. Azimuths | 21° 19' |\n| A. M. } | 35° 40' 13\" 4' | | pr. Amplitudes | 20° 39' |\n| P. M. } | 34° 58' 13\" 50' | | pr. Azimuths & Amplitudes | 18° 32' |\n| A. M. } | 34° 20' 14\" 20' | | pr. Azimuths & Amplitudes | 17° 27' |\n| | Funchal island of Madeira | | | |\n| 32° 33' 33\" 16' 49\" | | pr. Azimuths | 15° 30' |\n| 20° | Funchal island of Madeira | N. 76° E. dist. 19 leag. | pr. Azimuths | 16° 30' |\n| 22° | Salvages S. dist. 9 or 10 leag. | pr. Azimuths | 17° 50' |\n\nThese are taken from Dr. Heberden, F. R. S., who resided upon the island.\n| Time | Lat. in | Lon. in | Variation | How found | Means | Remarks |\n|------------|---------|---------|-----------|-----------|-------|---------|\n| | North | West | | | | |\n| 1768 | | | | | | |\n| September | | | | | | |\n| 23 | 29 40 | 15 30 | | | | |\n| P. M. D. | | | | | | |\n| A. M. | 29 7 | 15 50 | | pr. Amplitudes | 18 30 | |\n| | | | | pr. Azimuths | 16 30 | |\n| 24 P. M. | | | | pr. Azimuths | 16 43 | |\n| | | | | pr. Amplitudes | 15 46 | |\n| | | | | Ditto | 14 58 | Passage to Rio de Janeiro. |\n| 24 A. M. | 26 50 | 17 12 | | | | |\n| 25 P. M. | 25 20 | 18 50 | | pr. Amplitudes | 15 1 | |\n| | | | | pr. Sev. Azim. | 12 46 | |\n| | | | | Ditto | 12 43 | |\n| | | | | pr. Azimuths | 12 33 | |\n| 28 P. M. | 19 33 | 20 50 | | | | |\n| 29 P. M. | 18 38 | 21 0 | | | | |\n| October | | | | | | |\n| 1 P. M. | 15 40 | 22 0 | | Ditto | 10 37 | |\n| A.M. | 14 35 | 22 8 | | Ditto | 10 0 | |\n| | | | | Ditto | 11 40 | |\n| | | | | Amplitudes | 8 49 | |\n| 3 | | | | | | |\n| 5 P. M. | 11 53 | 22 0 | | pr. Azimuths | 6 10 | |\n| | | | | pr. Amp. 5 59 | 6 10 | |\n| 6 A. M. | 9 45 | 22 20 | | pr. S. Az. 6 21 | 8 52 | Towards Rio Janeiro. |\n| 8 P. M. | 9 42 | 22 19 | | Ditto | 9 0 | |\n| A.M. | 8 46 | 22 4 | | Ditto | 8 0 | |\n| | | | | 7 47 | 8 0 | |\n| | | | | Ditto | 8 23 | |\n| | | | | 8 20 | 8 21\\(\\frac{1}{2}\\) | |\n| 9 P. M. | 8 12 | 22 4 | | pr. Amplitudes | 7 48 | |\n| A.M. | 8 6 | 22 13 | | | | |\n| | | | | 7 48 | 8 39 | |\n| 10 P. M. | 7 48 | 22 13 | | pr. Sev. Azim. | 8 39 | |\n| 13 P. M. | 7 13 | 22 33 | | Ditto | 8 54 | |\n| 16 P. M. | 6 50 | 23 46 | | Ditto | 8 40 | |\n| | | | | Ditto | 4 2 | |\n| | | | | Amplitudes | 3 13 | |\n| | | | | pr. Azimuths | 3 17 | |\n| | | | | pr. Am. 2 16 | 2 24\\(\\frac{1}{2}\\) | |\n| 22 A. M. | 2 0 | 27 55 | | | | |\n| 25 P. M. | 0 55 | 28 55 | | | | |\n| Time | Lat. in | Lon. in | Variation | Remarks |\n|--------|---------|---------|-----------|---------|\n| | | | How found | Means |\n| | | | | |\n| 1768 October | | | | |\n| South West | | | | |\n| 27 A.M. | 2 3 | 31 0 | Ditto | 2 48 W. |\n| 29 P.M. | 3 59 | 32 30 | Ditto | 2 25 |\n| 30 P.M. | 5 46 | 32 48 | pr. Sev. Azim. | 1 31 |\n| 31 P.M. | 7 30 | 33 4 | Ditto | 0 15 |\n| November | | | | |\n| [P.M.] | 9 22 | 33 16 | Ditto | 0 58 |\n| [A.M.] | | | Ditto | 0 18 |\n| 2 P.M. | 10 3 | 33 0 | Ditto | 0 34 E. |\n| 3 P.M. | 12 27 | 33 0 | Ditto | 0 47 |\n| 4 P.M. | 15 25 | 33 40 | Ditto | 1 23 |\n| 7 P.M. | 18 30 | 36 10 | Ditto | 4 41 |\n| 8 P.M. | 20 4 | 37 18 | Ditto | 5 26 |\n| [A.M.] | 21 16 | 37 50 | Ditto | 7 52 |\n| 12 P.M. | Cape Forio W.N.W. dist. 12 leagues | | Ditto | 6 40 |\n| | Entrance Rio de Janeiro | | | |\n| | W.N.W. dist. 5 leagues | | | |\n| 13 P.M. | | | | 7 34 |\n| December | | | | |\n| [P.M.] | 25 44 | +1 4 | pr. Amplitudes | 8 40 |\n| [A.M.] | 26 0 | 41 20 | pr. Sev. Azim. | 8 23 |\n| 13 P.M. | 26 34 | 41 33 | Ditto | 8 23 |\n| 16 P.M. | 30 20 | 41 49 | Ditto | 9 36 |\n| 18 P.M. | 32 30 | 42 48 | Ditto | 11 3 |\n| 19 P.M. | 32 54 | 43 38 | Amplitudes | 11 3 |\n| 20 P.M. | 34 34 | +5 38 | pr. Sev. Azim. | 13 44 |\n| | | | | |\n| [P.M.] | 36 50 | 48 32 | Azim. 15 1 | 15 1 |\n| [A.M.] | 37 8 | 49 1 | Amp. 15 1 | 16 1 |\n| | | | pr. Amplitude | |\n| [P.M.] | 37 8 | 49 0 | pr.Az.15 24 | 15 45 |\n| [A.M.] | 36 46 | 49 2 | Amp. 16 5 | 15 30 |\n| | | | pr. Amplitude | |\n| | | | pr. D°. 16 12 | |\n| 29 P.M. | 41 40 | 56 25 | pr. Azimuth | 16 22 |\n| | | | pr. D°. 18 44 | |\n| | | | pr. Amplitude | 18 36 |\n| | | | | |\n\nTime\n| Time | Lat. in | Lon. in | Variation | Remarks |\n|----------|---------|---------|-----------|---------|\n| | | | How found | Mean |\n| 1769 | | | | |\n| January | | | | |\n| 5 P.M. | 48° 42' | 60° 51' | pr. Am. 20° 0' | 20° 4½ E. |\n| 9 P.M. | 51° 30' | 63° 30' | pr. Several Az. | 22° 24' |\n| 10 P.M. | 52° 40' | 65° 20' | Ditto | 21° 57' |\n| 11 A.M. | 54° 00' | 67° 30' | Ditto | 23° 30' |\n| | 10 leag. from Terra del Feugo | | | |\n| 21 A.M. | Strait le Mare | Ditto | 24° 9' | |\n| 22 A.M. | 56° 7' | 65° 45' | pr. Several Az. | 25° 4' |\n| | Near some isle on the coast of Terra del Feugo | ditto | 21° 0' |\n| | E. of C. Horne. | | | |\n| 24 | 55° 40' | | C. Horne S.W. | pr. Amp. 21° 16' |\n| | 3 W. 8 leag. | | | |\n| 25 A.M. | 55° 40' | | pr. Amp. 21° 16' | |\n| 28 P.M. | 57° 0' | 69° 0' | pr. Several Az. | 22° 0' |\n| 30 P.M. | 60° 10' | 74° 26' | Ditto | 27° 9' |\n| February | | | | |\n| 1 P.M. | 59° 23' | 76° 45' | Ditto | 24° 53' |\n| 3 P.M. | 58° 30' | 80° 58' | Ditto | 24° 4' |\n| 13 P.M. | 49° 13' | 89° 36' | Ditto | 17° 0' |\n| 15 P.M. | 48° 56' | 91° 27' | Ditto | 12° 0' |\n| 15 A.M. | 48° 10' | 92° 0' | Ditto | 11° 0' |\n| 21 A.M. | 44° 39' | 103° 0' | Ditto | 6° 30' |\n| 23 P.M. | 39° 43' | 105° 52' | Ditto | 5° 34' |\n| 27 A.M. | 39° 43' | 110° 26' | pr. Amp. 2° 17' | 2° 20½ |\n| | | | pr. Azim. 2° 24' | |\n| March | | | Ditto 2° 6' | |\n| 4 P.M. | 36° 49' | 111° 54' | Amp. 2° 46' | 2° 26' |\n| 8 P.M. | 37° 8' | 116° 8' | pr. Several Az. | 3° 13' |\n| 9 P.M. | 37° 24' | 117° 41' | Ditto | 4° 41' |\n| 10 P.M. | 35° 30' | 119° 30' | Ditto | 1° 42' |\n| 11 Ditto | 34° 0' | 121° 0' | Ditto | 4° 12' |\n| 12 Ditto | 32° 40' | 123° 0' | Ditto | 4° 23' |\n| | P.M. | | Amplitudes | 3° 20' |\n| 13 A.M. | 30° 56' | 125° 20' | pr. Azimuths | 3° 0' |\n\nPassage from Cape Horne to Ota-hitee.\n\nMean result of many azim. the sea calm and smooth.\n\nPassage from Cape Horne to Ota-hitee.\n| Time | Lat. in | Lon. in | Variation | Remarks |\n|--------|---------|---------|-----------|---------|\n| | | | How found | Means |\n| 1769 March | | | | |\n| South | | | | |\n| 15 P. M. | 30 30 | 126 0 | pr. Azimuths | 3 45 E. |\n| A. M. | 29 36 | 126 50 | Ditto | 3 22 |\n| 16 P. M. | 29 32 | 126 48 | pr. 21 Azimuths | 1 30 |\n| A. M. | 29 28 | 127 4 | Ditto | 2 18 |\n| 17 P. M. | 29 10 | 127 16 | Ditto | 3 27 |\n| A. M. | 27 40 | 129 20 | Ditto | 3 14 |\n| 21 A. M. | 25 21 | 129 28 | Amplit. 3 o | 3 21 1/2 |\n| | | | pr. Azim. 3 43 | |\n| 22 Ditto | 25 21 | 129 32 | Azimuth | 3 10 |\n| 28 P. M. | 21 14 | 127 38 | Amplitudes | 3 56 |\n| 29 P. M. | 20 29 | 127 44 | pr. Several Az. | 2 27 |\n| 31 P. M. | 19 30 | 129 10 | Ditto | 2 25 |\n| April | | | | |\n| 1 P. M. | 19 7 | 131 40 | Ditto | 2 32 |\n| P. M. | 18 46 | 138 0 | Ditto | 2 54 |\n| A. M. | 18 36 | 139 10 | Ditto | 2 54 |\n| 5 P. M. | 18 36 | 139 40 | Amplitude | 3 30 |\n| 8 P. M. | 17 48 | 143 50 | Several Azim. | 6 32 |\n| 9 P. M. | 17 36 | 145 30 | Ditto | 4 54 |\n| 10 P. M.| 17 42 | 146 16 | Ditto | 5 41 |\n| 11 P. M.| 18 0 | 147 59 | Ditto | 6 30 |\n| August | | | | |\n| 17 29 | 149 30 | Meridian line | 4 45 1/2 |\n| 18 A. M.| 17 15 | 151 41 | pr. Several Az. | 5 50 |\n| Ditto | 21 20 | 151 15 | Ditto | 5 40 |\n| 15 P. M.| 22 8 | 150 55 | Amplitude | 5 37 |\n| A. M. | 23 37 | 150 37 | Ditto | 6 7 |\n| 18 P. M.| 26 10 | 149 46 | Ditto | 8 8 |\n| A. M. | 26 30 | Ditto | Ditto | 7 58 |\n| 23 P. M.| 30 43 | 148 0 | Azimuths | 7 30 |\n| 24 A. M.| 32 40 | 147 14 | Ditto | 7 18 |\n| Ditto | 33 8 | 147 25 | Ditto | 6 40 |\n| Ditto | 38 3 | 147 6 | Ditto | 7 9 |\n| September | | | | |\n| 5 P. M.| 38 29 | 145 32 | Ditto | 7 0 |\n| Ditto | 33 0 | 153 0 | Ditto | 8 8 |\n\nOn shore at Fort Venus by four of Dr. Knight's compasses, which appeared to be all good.\n\nFrom the Society Isles to New Zealand.\n| Time | Lat. in | Lon. in | Variation | How found | Means | Remarks |\n|------------|---------|---------|-----------|-----------|-------|---------------------------------------------|\n| | | | | | | |\n| 1769 | | | | | | |\n| September | | | | | | |\n| South | | | | | | |\n| 19 P.M. | 29° | 159° | 42' | pr. Amplitudes | 8° 36' E. |\n| 19 A.M. | 29° | 159° | 25' | pr. Sev. Azim. | 8° 29' |\n| 25 P.M. | 33° 30' | 163° | 40' | Ditto | 10° 48' |\n| October | | | | | | |\n| 3 P.M. | 36° 50' | 173° | 46' | Ditto | 13° 22' |\n| 4 P.M. | 37° 6' | 174° | 46' | Ditto | 12° 48' |\n| 6 P.M. | 38° 33' | 179° | 0' | Ditto | 12° 59' |\n| 6 A.M. | 39° | 180° | 0' | Ditto | 14° 2' |\n| 7 P.M. | 39° 11' | 180° | 30' | Azim. 15° 4' | 15° 4½' |\n| 15 P.M. | 39° 37' | 182° | 30' | Ampl. 15° 5' | 14° 10' |\n| 17 A.M. | 40° | 182° | 0' | Ditto | 10° 22' |\n| November | | | | | | |\n| 9 | 36° 48' | 184° | 12' | Several Azim. | 11° 9' |\n| 25 | 35° 50' | 185° | 15' | Ditto | 12° 40' |\n| 26 | 35° 15' | Ditto | Amplitudes | 13° 10' |\n| 28 | 35° | 185° | 30' | pr. Azimuths | 11° 45' |\n| December | | | | | | |\n| 8 | 34° 42' | 185° | 30' | pr. Amplitude | 12° 51' |\n| 10 P.M. | 34° 40' | 186° | 15' | Azim. 12° 40' | 12° 40' |\n| 11 P.M. | 34° 40' | 186° | 45' | Ampl. 12° 40' | 12° 20' |\n| 25 A.M. | 34° | 188° | 0' | Several Azim. | 11° 25' |\n| 1770 | | | | | | |\n| January | | | | | | |\n| 6 A.M. | 35° | 188° | 0' | Ditto | 12° 26' |\n| 12 P.M. | 38° 12' | 185° | 3' | Ditto | 15° 0' |\n| 12 A.M. | 39° | Ditto | Ditto | 14° 15' |\n| 14 P.M. | 39° 40' | Ditto | pr. Amplitudes | 13° 0' |\n| 15 A.M. | 40° 30' | 186° | 0' | Azimuths | 13° 5' |\n| February | | | | | | |\n| 11 A.M. | 41° | 183° | 0' | pr. Amplitudes | 14° 0' |\n| 12 P.M. | 41° 26' | 184° | 0' | Ditto | 14° 0' |\n| 14 Ditto | 42° 8' | 184° | 15' | Azim. 15° 8' | 15° 4' |\n\nIn sight of the East coast of New Zealand.\n\nOff the Northern parts of New Zealand.\n\nWest coast.\n| Time | Lat. in | Lon. in | Variation | How found | Means | Remarks |\n|--------|---------|---------|-----------|-----------|-------|---------|\n| | | | | | | |\n| **1770** | | | | | | |\n| February | | | | | | |\n| South | | | | | | |\n| 17 A.M. | 44° 0' | 186° 30' | Ditto | 14° 32' | 14° 24' E. | |\n| Ditto | 45° 0' | 186° 15' | Ditto | 14° 16' | 15° 36' | |\n| March | | | pr. Amplitudes | | | |\n| 1 P.M. | 47° 34' | 187° 30' | pr. Azimuths | 16° 34' | | East coast. |\n| 4 A.M. | 46° 30' | 189° 0' | Ditto | 16° 16' | | |\n| 7 P.M. | 46° 54' | 191° 0' | Amplitude | 15° 10' | | |\n| 7 A.M. | 47° 0' | Ditto | pr. Azimuths | 15° 56' | | |\n| 9 P.M. | 47° 12' | 191° 30' | pr. Amplitudes | 16° 29' | | |\n| 15 P.M. | 45° 0' | 192° 30' | Ditto | 15° 2 | | |\n| Ditto | 44° 27' | 191° 15' | pr. Azimuths | 13° 48' | | West coast. |\n| 25 A.M. | 40° 30' | 186° 0' | pr. Amplitudes | 12° 20' | | |\n| April | | | | | | |\n| 7 P.M. | 37° 15' | 196° 40' | Several Azim. | 13° 50' | | |\n| 8 P.M. | 37° 40' | 197° 40' | Ditto | 13° 56' | | |\n| 10 A.M. | 38° 45' | 202° 23' | Ampl. 11° 25' | 11° 22½' | | Between New Zeland and New Holland. |\n| | | | Azim. 11° 20' | | | |\n| | | | Amplitude | | | |\n| | | | Azimuth | | | |\n| 13 P.M. | 39° 15' | 203° 40' | Ditto | 12° 25' | | |\n| 13 A.M. | 39° 23' | 204° 0' | Ditto | 12° 29' | | |\n| 14 P.M. | 39° 24' | 204° 4' | Amplitude | 11° 28' | | |\n| 14 A.M. | 39° 23' | 204° 15' | Azimuth | 11° 30' | | |\n| 20 A.M. | 37° 0' | 210° 0' | Ditto | 10° 40' | | |\n| 21 P.M. | 36° 35' | 210° 0' | Ditto | 10° 42' | | |\n| 22 A.M. | 35° 35' | 209° 23' | Ditto | 9° 50' | | |\n| Ditto | 35° 35' | 209° 0' | Ditto | 7° 41' | | |\n| 25 P.M. | 35° 18' | 209° 11' | Ditto | 9° 15' | | |\n| 25 A.M. | 34° 0' | 208° 50' | Ampl. 9° 36' | 9° 21½' | | |\n| | | | Azim. 9° 7' | | | |\n| 26 P.M. | 34° 18' | 208° 49' | Several Azim. | 8° 48' | | |\n| May | | | | | | |\n| 7 P.M. | 33° 50' | 208° 37' | Ditto | 8° 0 | | |\n| 7 A.M. | 33° 22' | 208° 20' | D° with needles | 7° 56' | | |\n| 8 P.M. | Ditto | | Azimuths | 8° 25' | | |\n| 10 | 33° 13' | 207° 20' | Ditto | 8° 0 | | |\n| 11 A.M. | 32° 40' | 206° 36' | pr. d° and Amp. | 9° 10' | | |\n| 18 | 26° 20' | 206° 46' | pr. Azimuths | 8° 40' | | |\n| 19 P.M. | 25° 34' | 206° 45' | Ditto | 8° 36' | | |\n| | 25° 24' | 206° 38' | pr. Amplitudes | | | |\n| | | | pr. Azimuths | 8° 21½' | | |\n\n*Time*\n| Time | Lat. in | Lon. in | Variation | Remarks |\n|--------|---------|---------|-----------|---------|\n| | | | How found | Means |\n| 1770 May | South | | | |\n| 20 P. M. | 25 12 | pr. Azimuth | 8 45 E. |\n| {P. M.} | 24 34 | pr. Amplitude | 8 3 |\n| {A. M.} | 24 25 | Azimuths | 7 50 |\n| 26 P. M. | 23 24 | Ditto | 7 28 |\n| June | | | | |\n| 3 A. M. | 20 20 | Ditto | 6 57 |\n| 5 A. M. | 19 18 | Amplitude | 5 35 |\n| 6 A. M. | 19 4 | Ditto | 5 31 |\n| {P. M.} | 19 0 | Amplitude | 5 25 |\n| {A. M.} | 18 52 | Ditto | 5 0 |\n| 9 A. M. | 16 59 | Ditto | 4 53 |\n| August | | | | |\n| 23 P. M. | 10 36 | Amplitude | 2 54 |\n| 27 A. M. | 10 3 | Ditto | 2 30 |\n| 28 P. M. | 9 51 | Ditto | 2 51 |\n| September | | | | |\n| 2 P. M. | 7 39 | Ditto | 2 34 |\n| 3 Ditto | 7 2 | Ditto | 2 4 |\n| 4 P. M. | 6 18 | Ditto | 2 30 |\n| 9 P. M. | 9 36 | Azim. o 12 | o 8 3 W. |\n| Amp. o 5 | | | | |\n| 10 A. M. | 9 50 | Ditto | o 2 |\n| 13 Ditto | 9 40 | Amp. i 10 | i 18 1/2 |\n| Azim. i 27 | | | | |\n| 14 Ditto | 9 50 | Amp. and Azim. | 2 4 |\n| 17 P. M. | 10 8 | Amplitude | 1 49 |\n| 24 Ditto | 11 10 | pr. Several Azim. | 2 44 |\n| 27 Ditto | 11 10 | Ditto | 3 10 |\n| 1771 January | | | | |\n| 27 P. M. | 10 | Ditto | 2 51 |\n| February | | | | |\n| 3 P. M. | 15 52 | Ditto | 2 56 |\n| 7 P. M. | 18 34 | Ditto | 3 24 |\n| 14 P. M. | 21 56 | Ditto | 4 10 |\n\nTime\n| Time | Lat. in | Lon. in | Variation | How found | Means | Remarks |\n|--------|---------|---------|-----------|-----------|-------|---------|\n| | | | | | | |\n| **1771** | | | | | | |\n| February | | | | | | |\n| 17 P. M. | South | West | pr. Several Azim. | 23° 20' | 20° W | |\n| 20 P. M. | | | Ditto | 24° 57' | 12° 15' | Java head to the Cape of Good Hope. |\n| 23 P. M. | | | pr. Amplitude | 26° 59' | 17° 30' | |\n| 25 P. M. | | | pr. Azimuth | 27° 55' | 24° 20' | |\n| 26 P. M. | | | pr. Amplitude | 28° 40' | 24° 0' | |\n| March | | | Azimuths | 28° 54' | 26° 10' | |\n| 4 P. M. | | | Ditto | 31° 8' | 25° 35' | |\n| 8 A. M. | | | Amp. 28° 30' | 34° 20' | 28° 19' | |\n| 10 P. M.| | | Azim. 28° 8' | 35° 40' | 24° 0' | |\n| 12 P. M.| | | pr. Amplitude | 34° 54' | 22° 30' | |\n| April | | | Ditto | Table Bay, Cape of Good Hope. | 20° 30' | |\n| 23 P. M.| | | Amplitude | 27° 12' | 17° 40' | By several observations. From the Cape of Good Hope to England. |\n| 24 A. M.| | | Azimuth | 26° 34' | 18° 37' | |\n| 24 P. M.| | | Amplitude | 26° 12' | 17° — | |\n| 28 P. M.| | | Amp. and Azim. | 25° 26' | 17° 30' | |\n| 29 Ditto| | | Azimuth | 19° 50' | 14° 0' | |\n| May | | | Ditto | 18° 30' | 13° 53' | |\n| 5 A. M. | | | Ditto | 15° 25' | 13° 10' | |\n| 7 Ditto | | | Ditto | 12° 30' | 12° 50' | |\n| 9 P. M. | | | Ditto and Amp. | 10° 24' | 11° 00' | |\n| 13 A. M.| | | Azimuth | 3° 18' | 10° 00' | |\n| North | | | Ditto | | | |\n| 19 Ditto| | | Amplitude | 4° 20' | 7° 40' | |\n| 23 Ditto| | | Azimuth | 7° 40' | 9° 40' | |\n| 26 Ditto| | | Ditto | 10° 38' | 6° 30' | |\n| 31 Ditto| | | Ditto | 18° 25' | 5° 9' | |\n| June | | | Ditto | | | |\n| 1 A. M. | | | Ditto | 20° 0' | 6° 40' | |\n| 2 Ditto | | | Ditto | 21° 4' | 5° 4' | |\n| 4 Ditto | | | Ditto | 23° 30' | 4° 30' | |\n| 6 Ditto | | | Ampl. 5° 5' | 25° 40' | 5° 34½' | |\n| | | | Azim. 6° 4' | | | |\n| Time | Lat. in | Lon. in | Variation | How found | Means |\n|--------|---------|---------|-----------|-----------|-------|\n| | | | | | |\n| 1771 June | North West | | | | |\n| 7 A. M. | 27 22 | 43 43 | 20 Azimuths | Ditto | 5 20 W. |\n| 8 Ditto | 28 30 | 43 42 | Amp. 7 3 | Azim. 7 30 | 5 24 |\n| 9 Ditto | 29 51 | 44 9 | Ampl. 9 18 | Azim. 9 — | 7 17 |\n| 10 P. M.| 30 26 | 44 15 | Amplitude | Azimuths | 9 9 |\n| 12 P. M.| 32 16 | 45 14 | Amplitude | Azimuths | 7 0 |\n| A. M. | 32 40 | 45 0 | Azimuths | Azimuths | 6 55 |\n| P. M. | 33 16 | 44 53 | Azim. and Amp. | Ampl. 8 15 | 8 23 |\n| A. M. | 33 53 | 44 25 | Azim. 8 14 | Azimuths | 8 14½ |\n| 14 P. M.| 34 36 | Ditto | Amplitude | Azimuth | 8 14 |\n| 17 Ditto| 38 26 | 40 20 | Azimuth | Azimuth | 9 1 |\n| P. M. | 39 12 | 39 0 | Azim. 14 13 | Ampl. 14 18 | 14 15½ |\n| A. M. | 39 22 | 38 0 | Amplitude | Azimuth | 14 24 |\n| P. M. | 43 55 | 17 16 | Azimuth | Ditto | 18 30 |\n| A. M. | 44 30 | 16 18 | Ditto | Azimuths | 19 30 |\n| July | | | | | |\n| 1 P. M. | 44 40 | 15 44 | Azimuths | Ditto | 23 0 |\n| A. M. | 44 50 | 16 10 | Ditto | Ditto | 22 50 |\n| 3 P. M. | 45 — | 13 0 | Azimuths | Azimuths | 20 36 |\n| 4 P. M. | 45 30 | 10 45 | Azimuths | Azimuths | 21 25½ |\n| A. M. | 45 20 | 9 37 | Amplitudes| Amplitudes| 21 10 |\n| 7 P. M. | 45 45 | 8 38 | Amplitude | Azimuths | 22 30 |\n\nExtract\nExtract from Capt. Cook's Journal.\n\nNov. 9 At 8 A. M. Mr. Green and I went on shore, to observe the Transit of Mercury, which came on at $7^h\\ 20'\\ 58''$ apparent time, and was observed by Mr. Green alone; I at this time was taking the Sun's altitude in order to ascertain the time.\n\nMr. Green \\begin{align*}\n\\text{Internal contact} & \\quad h\\ v\\ '' \\\\\n12 & \\quad 8\\ 58 \\\\\n\\text{External contact} & \\quad 9\\ 55\n\\end{align*}\n\nC. Cook \\begin{align*}\n\\text{Internal contact} & \\quad P. M. \\\\\n— & \\quad 8\\ 45 \\\\\n\\text{External contact} & \\quad 9\\ 48\n\\end{align*}\n\nLat. observed at noon $36^\\circ\\ 48'\\ 28''$, the mean of this and yesterday observations gives $36^\\circ\\ 48'\\ 5\\frac{1}{2}''$ South, the latitude of the place of observation. The variation of the compass was found to be $11^\\circ\\ 9'$ East.\n\n** These observations were made by the help of a Graham's watch with a second hand; corrected by observed altitudes of the Sun.\n\nXLV. Transitus", "source": "olmocr", "added": "2026-01-12", "created": "2026-01-12", "metadata": { "Source-File": "/home/jic823/projects/def-jic823/royalsociety/pdfs/106114.pdf", "olmocr-version": "0.3.4", "pdf-total-pages": 12, "total-input-tokens": 18402, "total-output-tokens": 12195, "total-fallback-pages": 0 }, "attributes": { "pdf_page_numbers": [ [ 0, 0, 1 ], [ 0, 1794, 2 ], [ 1794, 5379, 3 ], [ 5379, 7800, 4 ], [ 7800, 10145, 5 ], [ 10145, 12399, 6 ], [ 12399, 15657, 7 ], [ 15657, 19124, 8 ], [ 19124, 20740, 9 ], [ 20740, 23624, 10 ], [ 23624, 25242, 11 ], [ 25242, 26188, 12 ] ], "primary_language": [ "en", "en", "en", "en", "en", "en", "en", "en", "en", "en", "en", "en" ], "is_rotation_valid": [ true, true, true, true, true, true, true, true, true, true, true, true ], "rotation_correction": [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ], "is_table": [ false, true, true, true, true, true, true, true, true, true, true, false ], "is_diagram": [ false, false, false, false, false, false, false, false, false, false, false, false ] }, "jstor_metadata": { "identifier": "jstor-106114", "title": "Variation of the Compass, as Observed on Board the Endeavour Bark, in a Voyage Round the World. Communicated by Lieut. James Cook, Commander of the Said Bark", "authors": "James Cook", "year": 1771, "volume": "61", "journal": "Philosophical Transactions (1683-1775)", "page_count": 12, "jstor_url": "https://www.jstor.org/stable/106114" } }