MAGNETIC INSPECTION TRIP AND OBSERVATIONS DURING TOTAL SOLAR 

 ECLIPSE OF APRIL 28, 1911, AT MANUA, SAMOA.' 



By L. a. Bauer. 

 PURPOSE AND EQUIPMENT. 



In 1911 I visited, en route to join the Carnegie at Colombo, Ceylon, various scientific 

 institutions and magnetic observatories in the Orient and conferred with various persons 

 respecting cooperative magnetic work. Leaving Washington, D. C, on March 16, 1911, 

 I proceeded to Colombo via Vancouver, Honolulu, Suva, Auckland, Christchurch, Sydney, 

 Melbourne, and Perth, being due at Colombo about the middle of June. According to 

 the steamer schedules, I would have a wait of about three weeks at Suva, Fiji, before 

 connections could be made for New Zealand. 



A total eclipse of the Sun was to occur at certain places in the Pacific Ocean on April 

 28, 1911 (Plate 10, Fig. 2). All the observing parties, of which I had heard, had decided 

 to congregate at various points in the Tonga Islands. The most important of these expedi- 

 tions were those of the British and the Australian astronomers, which were exceedingly 

 well equipped and for which most elaborate preparations had been made. So far as I knew, 

 however, no party essayed reaching any other island, though by so doing the chances 

 would be multiplied of getting results in case the parties in the Tongas were unfortunate 

 as to weather. Consulting the time tables, I found that we were due at Suva, Fiji, on 

 April 10, but 18 days before the eclipse and a week or more after the other parties would 

 already have been engaged on the necessary preparatory work at their respective stations. 

 At Suva, unfortunately, the eclipse was only to be a partial one and it would be necessary 

 to travel almost 1,000 miles or more eastward to reach a desirable point. 



As will be seen from Fig. 2 (Plate 10), the actual line of central eclipse commenced 

 on the southeast portion of Australia, and passed in a northeast direction, crossing the 

 ccjuator in about longitude 154 W. It then swept eastward, terminating in about longitude 

 90 W. just off the west coast of Central America. The line thus extended over the full 

 width of the Pacific Ocean. WTiile there are many islands in this ocean, there were, 

 unfortimately, remarkably few which laj' in the narrow band of the totality track. Fol- 

 lowing the line from west to east, the first suitable station that one finds is Tofua, in the 

 Tonga or Friendly Islands. The next that is met with is Vavau, in the same group, and also 

 close to the central line of totality. Most of the eclipse parties were located near this 

 station. INIuch farther eastward we reach Nassau, which lies a little to the south of the 

 central line, but well within the central zone; and not far away are the Danger Islands, 

 which are situated to the north, but farther away from the central line. To reach Nassau 

 or Danger Islands would require a specially chartered steamer, and landings on them, on 

 accoimt of breakers, are not always possible. Manua Island, of the Samoan group, on 

 the western edge of the belt, appeared to be the most feasible station in the east to make 

 a try for within our limited tijiie. 



Inquiries made, however, both at Washington and Vancouver, had indicated that the 

 chances were exceedingly small of connections being made at Suva with any vessel for the 

 Samoan Islands whence I might proceed to the tentatively chosen eclipse station. It was, 

 nevertheless, thought worth while to take along a limited equipment to be utilized in case 

 I was fortunate enough in my connections. I was primarily interested in attempting 

 once more to discover whether there was an appreciable effect on the Earth's magnetism 

 during a total solar eclipse.^ Stress was, accordingly, laid on the magnetic outfits, of 



'A preliminary account was published in Science, July 28, 1911, p. 105. 



'For the results of previous work, see Terr. Mag., vol. 5, 1900, pp. 143-165; vol. 7, 1902, pp. 155-192. 



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