26 



LIEUT.-COLONEL SABINE ON TERRESTRIAL MAGNETISM. 



determinations, the " corrections for epoch" and the uncertainties consequent there- 

 upon, bear to the probable amount of the combined instrumental differences and ob- 

 servation errors of independent careful observers ; and, consequently, the importance 

 of the synchronism so much insisted upon, of the observations which are to concur 

 in determining the magnetic state of the globe at the present period. 



Inclination. — The inclinations contained in Table IX. were observed with a six- 

 inch instrument by Robinson, with a needle by the same artist. The poles of the 

 needle were reversed on every occasion, and the observations were repeated in the 

 eight different positions of the circle and needle. Usually five repetitions were made 

 in each position, and the arcs at both ends of the needle being read, the inclinations 

 in the Table are generally a mean of eighty readings. 



Table IX. — Observations of the Inclination. 



Station. 



Panama s 



Magnetic Islands 



Oahu 



Port Etches 



Sitka < 



San Bias. . . . , 



San Francisco 



Acapulco . . , 

 Realejo ..... 

 Cocos Island 

 Callao 



Puna Island 

 (Guayaquil) 



Cocos Island .... 



Oahu } 



Kodiack 



Sitka 



Baker's Bay . . . . 



Fort Vancouver < 



Port Bodega . 



San Francisco 



Date. 



1837. 



March 8 



March 8 



March 20 



March 22 



July 20 and 24 . 

 August 26 and 28 

 September 20 . . 

 September 22 . . 

 December 21 . . 

 December 22 . . 

 December 22 . . 

 December 29 



1838. 

 January 18 

 March 19 and 21 

 April 6 

 June 1 9 and 23 

 September 17 

 Septenrber 20 

 September 21 

 September 24 



1839. 



March 7 



June 

 June 

 June 

 July 

 July 



1 



6 .... 



7 .... 

 7 .... 



19 .... 

 September 13 

 August 12 . . 

 August 12 . . 

 September 25 

 September 30 

 September 30 

 October 1 . . 

 October 1 . . 

 October 2 . . 



Poles. 



Direct. Reversed. 



30 

 30 

 30 

 30 

 40 

 76 



58-8 

 54-6 

 27-5 

 08-5 

 43-4 

 02-2 

 75 47-5 

 75 49-1 

 44 20-2 

 44 12-8 

 43 59-2 

 61 18-9 



36 

 33 



22 



— 4 



8 



51-2 

 13-6 

 29-2 

 20-9 

 09-4 

 58-1 

 22-3 

 10-5 



26-6 

 24-9 

 12-5 

 36-2 

 28-1 

 43-4 

 27-5 

 15-9 

 69 20-2 

 62 50-6 

 50-2 

 37-1 

 52-3 

 52-3 

 50-2 



21 

 40 

 40 

 40 



72 

 75 



^^ 



69 



61 

 61 

 61 

 61 

 61 



53-2 

 51-0 

 01-5 

 10 

 27-6 

 03-6 

 53-8 

 55-5 

 30-2 

 46 34-0 

 45 26-3 

 62 28-7 



32 

 32 



32 

 32 



42 

 76 

 75 

 75 

 46 



39 

 36 



24 

 -8 



9 



10 

 10 



9 



03-7 

 00-2 

 36-9 

 07-7 

 11-1 

 15-8 

 27-9 

 31-2 



24 



42 

 42 



42 



72 



24-9 

 15-0 

 09-7 

 02-6 

 57-6 

 75 54-9 

 69 26-2 

 23-6 

 28-9 

 56-2 

 16-0 

 16-0 

 25-7 

 22-9 

 25-7 



69 

 69 

 62 

 62 

 62 

 62 

 62 

 62 



Inclination. 



69 



ii-o\ 



>2-8/ 



31 5] 



31 52- 



31 14-5 1 



31 09-3/ 



75 50-6 



75 52-3 



45 25-2 



45 23-4 



9 25 

 8 50 



■I] 



41 19-9 

 41 IM 

 41 19-4 



19-81 

 24-6/ 



62 03-1" 



61 56-6 



62 09-0 

 62 07-6 

 62 08-0 



31 51-9 



31 11-9 



41 35-1 

 76 02-9 



75 51-5 



45 24-3 



44 42-7 

 61 53-8 



37 57-4 

 34 36-9 

 23 33-2 

 ■ 6 14-3 



8 40-2 



9 36-9 



9 08-0 



22 55-7 



41 16-8 



72 42-9 



75 49-1 



69 26-9 



&^ 22-2 



62 53-4 



62 05-0 



Remarks. 



Near the Ruins of the Con- 

 vent of San Francisco. 



Observation Island. 



Palm Island. 



Beach near the Arsenal. 

 Yerba Buena. 



Near the Castle. 

 Cardon Island. 



Plaza de los Muertes. 

 Punta Arena. 

 Tow^n of Puna. 



P' Spanola. 



Near P' Greville. 



On the Sandy Neck. 



