June 22, 1911] 



NATURE 



56; 



THE BRITISH SOLAR ECLIPSE EXPEDITIOX.' 



T.S.S. " Marama," 



Pacific Ocean, 



May 20, 191 1. 

 l\/f Y last letter was very brief, as the ss. Bouverie, the 

 steamer which ran on a coral reef and was sub- 

 sequently got off, arrived unexpectedly at Vavau on her 

 way to' San Francisco. This meant that a mail could 

 be sent by her, but only a short letter was written in 

 consequence. 



Although this letter is sent by the following mail to 

 England, it happens that I am travelling in that par- 

 ticular mail steamer which is bound for Vancouver. 

 We have therefore had a considerable time now to consider 

 past events, and, incidentally, I have 

 been down with a sharp attack of fever 

 which I managed to pick up at Fiji ; 

 we are now three days off Honolulu, 

 and I am convalescent. 



Although during the first ten days of 

 our stay at Vavau the weather condi- 

 tions were all that could be desired for 

 eclipse work, they gave way slowly to 

 quite a different type ; while rain had 

 been the exception, it now became a 

 daily occurrence, and not only did it 

 rain, but it came down in torrents. 

 This change of weather put quite a 

 different complexion on our prospects. 

 Nevertheless we worked and hoped for 

 the best, but still the nearer the eclipse 

 day approached the worse the weather 

 became. On the day before the eclipse 

 my notes regarding the weather are as 

 follows : — " To-day would have been a 

 bad day for the eclipse. There is a 

 great amount of high cirrus which 

 would have prevented good photographs 

 from being secured, and the presence 

 of low drifting cumuli would most prob- 

 ably have totally blotted out the sun 

 for some period during totality. I ex- 

 pect the conditions to-morrow will be 

 somewhat like Palma over again, but I 

 hope the cloudy part will occur at third 

 contact and not at second contact as it 

 did there." 



Luck was against us, however. 

 Eclipse morning broke, and this was 

 the cloudiest we have experienced. 

 Cirro cumulus cloud in the form of 

 waves extended over a considerable part 

 of the sky, and low cumuli of various 

 sizes were numerous. There was 

 sufficient sun at intervals for all the 

 instruments to be set and kept running, 

 and I went round all the individual 

 instruments and critically examined the 

 definition of the solar images on the 

 ground-glasses. Everything was most 

 satisfactory. 



I had arranged that all the working 

 parties should be ashore at 7 a.m., and 

 that the remainder should arrive half 

 an hour later. The camp assumed a 



most business-like air, and everyone seemed glad that the 

 day had at last arrived. I had taken the precaution to dis- 

 tribute parties as far apart as possible that could be dis- 

 tributed, and with this object I sent one party off early in 

 the morning to take up their position on Talau Hill, 400' 

 feet high and about three miles distant. This party con- 

 sisted of observers for stars, shadow phenomena, and 

 drawing the corona, and a small camera party. On 

 another hill, 200 feet high and half a mile away, a second 

 similarly constituted party was dispatched. A special party 

 was also on board, and men placed at the mastheads. 



Alas ! with all these precautions no party saw the sun 

 free from clouds. There is little doubt that, as the moon 

 gradually covered the sun and a natural reduction of the 

 1 Coneinued from p. 529. 

 NO. 2173, VOL. 8dJ 



air temperature took place, the tremendously moist atmo- 

 sphere gradually condensed in the form of cloud, which 

 became denser the nearer totality approached. Some 

 minutes before second contact a very large black, dense 

 cumulus with billowy tops came sweeping up from the 

 eastward, and this cloud it was that practically sealed our 

 doom. Onward it came, and just before second contact 

 its outliers began to cover the sun and then totally eclipse 

 it. The presence of the clouds made the image of the 

 cusp very difficult to observe, as it was jumping up and 

 down on the card. The cusp observer had eventually to 

 give the signals from the chronometer alone. 



Three whistles, two whistles, and one whistle were the 

 signals to precede the order "go," and at "go" the 

 whole camp began their combined effort. I fired ofl my 



first four instantaneous exposures, and then one of a few 

 seconds, and then a long one. During this last I went 

 out of my tent with opera-glasses and card and pencil to 

 draw the corona, when, alas! I could not even see where 

 the sun ought to be. The large ominous black cloud h.nd 

 completely blotted out the whole region. I returned to my 

 tent very' sad ; at a later long exposure I emerged once 

 more, and there was the silvery corona as rigid as an 

 Indian order suspended in the sky. It was shorn of most 

 of its beauty, for the cirrus cloud was verj^ thick, and 

 must have absorbed a great amount of light. There was 

 no doubt about its form, however, for at a glance it repre- 

 sented the minimum type known as the wind vane. 



Something extraordinary, however, seems to have 

 happened. While the timekeeper shouted out twenty, i.e. 



