15 



is subject to great doubt, from the smallness of the number of the 

 observations at the late period of the year. 



The results however are entitled to rather more consideration in 

 this respect, that, with regard to the greater numbers of the stars 

 that are physically unexceptionable (that is, omitting binary stars, 

 and those whose components are of equal magnitude), the directions 

 of apparent change of position are favourable to the supposition of a 

 measurable parallax. This is particularly the case with respect to 

 32 Eridani and Herschel 95, which the author in conclusion recom- 

 mends to the notice of astronomers provided with adequate instru- 

 ments for observing them. 



2. "Magnetic Survey of the Eastern Archipelago." By Cap- 

 tain C. M. Elliot of the Madras Engineers. Communicated by 

 Lieut-Col. Sabine, V.P. Treas. R.S. &c. Received Jan. 15, 185i. 



In the year 1845, the Committee of Physics of the Royal Society 

 having expressed a wish that a Magnetic Survey should be made 

 of the East Indian Archipelago, Captain Elliot was ordered by the 

 Court of Directors of the East India Company to undertake that 

 duty, after the close of the Singapore Magnetic Observatory. The 

 observations at that observatory were discontinued at the end of the 

 year 1845, but the instruments were still allowed to remain, that 

 the portable instruments might be occasionally compared with them 

 during the Survey. 



The object which the author proposed to himself was the deter- 

 mination of certain magnetic lines within the limits of the Survey : 

 the lines of no dip, and of the maximum horizontal component of 

 the earth's force ; the minimum intensity of the total magnetic force ; 

 and finally, the line of no declination. He was also desirous of ob- 

 serving the variations of the magnetic elements, and of ascertaining 

 whether the changes of the declination, of magnetic intensity, and 

 of the barometer, were uniformly similar over so large an area. 

 The fixed stations for this latter purpose were sixteen in number, 

 and the time employed at each station varied from a few days to 

 several months. They were spread over an area of 28° of latitude, 

 and more than 40° in longitude, viz. from 16° latitude north to 12° 

 south, and from 80° to 125° longitude east. This part of the globe 

 coincides very nearly with the position of minimum total force. Of 

 the sixteen stations, nine were to the south of this line, three to the 

 north, and four in its immediate vicinity. Four stations were in the 

 islands adjacent to Singapore ; one in Borneo ; one in the island of 

 Java; two in Sumatra ; one in the island of Mindanao ; one in Ce- 

 lebes ; one at the Cocos or Keeling Islands, which was the most 

 southern station to which Capt. Elliot could venture ; one at Penang, 

 and one in its immediate vicinity ; one at Nicobar, an island in the 

 Bay of Bengal; one at Moulmein, which was the most northerly, 

 and one at Madras, which was the extreme westerly, station. The 

 total number of days employed in observing at the fixed stations 

 amounted to 496. The instruments employed at the fixed stations 

 were, for the changes of declination, sometimes three, but never less 



