May 26, 1910] 



NA TURE 



O^D 



the results were negative ; neither the visual nor the photo- and to have led to some eccentric precautions, such as an 

 graphic observations revealed any certain trace of the oxygen-supplied sealed room, &c. The accounts of 

 comet during its transit of the sun's disc. The day was prayer-meetings held by negroes in the southern States, and 

 cloudy, but the definition was splendid, and the comet's of general absolution being given by Italian priests, vividly 

 tail had been easily seen in the early morning. It there- recall the Biela scare of 1882, when Holmes's comet was 

 fore seems certain that the tenuit>- of the matter forming discovered. 



the head of Halley's comet has not been overstated. Unfortunately, astronomers and sensationalists alike have 



In England the sun did not rise until, according to been disappointed. .According to Johannesburg observa- 

 computation, seven-tenths of the passage was effected, and tions on Thursday, the tail was seen still well above the 

 bad weather effectually prevented any possibility of ecliptic, and observations generally failed to indicate any 

 observation. In a telegram to the Daily Mail Prof. Dyson phenomena which might assuredly be connected with an 

 reports that the sky was clear, on May 19, from i a.m., encounter. Careful preparations were made to observe 

 but no meteors, aurora, or other unusual phenomena were possible magnetic disturbances, aurora;, and meteors, all 

 seen at the Edinburgh Obser\ator}% The reports from or any of which might be produced by the earth's passage 

 the African and Australian observatories are similarly through a charged, meteoric agglomeration. The magnets 

 n^ative. at Greenwich indicated no abnormal disturbance on 



The Rev. Dr. A. Irving writes, however, from Bishop's May 19, but, according to Reuter, Prof. Birkeland's instru- 

 Stortford on May 18 as follows : — ments at Finmarken registered a well-marked magnetic 



" We are here at about 250 O.D. and well away from - storm on that day, although the days before and after 

 the London atmosphere. The day has been overcast until were exceedingly quiet. Prof. Birkeland ascribes this to 

 about 4 p.m., but 

 the later hours have 

 been clear. I have 

 looked for anything 

 abnormal, but have 

 not been able to 

 observe anything 

 beyond a slight and 

 diffused haze, which 

 seemed to be per- 

 haps more con- 

 tinuous than usual 

 into the upper strata 

 of the atmosphere. 

 At sunset the 

 western sky was 

 clear of clouds, but 

 the glow was quite 

 an ordinary occur- 

 rence, except that it 

 seemed somewhat 

 fainter than usual 

 with such a sky. 

 But I do not recol- 

 lect having ever seen 

 a sunset in such a 

 sk\' with such feeble 

 after-effects. It may 

 be said that there 

 was no after-glow 

 at all : merely a 

 dull grey effect, as 

 if the comet's tail 

 had no effect beyond 

 acting as a sort of 

 screen to the sun's 

 rays. It might be 

 interesting to know 

 if similar ' naked- 

 eye ' observations 

 were made by 

 others." 



The time of the passage of the earth through the 

 extremely tenuous tail was, and apparently still is, un- 

 certain. A week or so before the passage was due there 

 appeared to be some doubt whether the tail was sufficiently 

 long to reach the earth, but this was dispelled by the 

 later observations. Prof. Barnard, on May 18, traced it 

 to a distance of 107° from the head, which implies an 



I actual length of more than fifty million miles, more than 



1 three times the necessary extent. 



I But the actual curvature of the tail could not be deter- 



' mined, and in that lay the uncertainty- as to a passage 

 taking place; for the same reason the time of the earth's 

 passage was indeterminable, although Dr. Franz calcu- 

 lated that it should occur some time later on May 19. 

 Observations at Johannesburg indicate that the earth ! cometar>- intiuence, for the general meteorological situa- 



FiG. 3 — Halley's Comet as seen at Malta on May 14 by Mr. C. Leacb. 



electrical effects produced by the passage of the earth 

 through the charged cometary matter, and has secured 

 excellent magnetograms and earth-current curves, as 

 well as valuable electrical and meteorological observa- 

 tions. 



The reports received at the Meteorological Office con- 

 tain no references to unusual meteorological phenomena 

 which may be associated with Halley's comet. Thunder- 

 storms occurred on each day of the week in some part of 

 the United Kingdom. A sharp storm in the south-east of 

 England in the early morning of Thursday, May 19, just 

 about the time of the calculated transit of the earth through 

 the comet's tail, attracted much attention. It would, how- 

 ever, be rash to attribute their electrical manifestations to 



passed under the tail on Saturday morning. 



The possibility of this occurrence appears to have 

 incited a great deal of fear and excitement, despite the 

 explicit statements of well-known astronomers that any 

 catastrophe was improbable in the extreme. The fear of 

 poisoning by cyanogen seems to have been the best defined, 



NO. 2 II 7, VOL. Sy\ 



tion, which was characterised by high pressure over 

 Scandinavia and low pressure over the Bay of Biscay, 

 was of a type which in summer is generally associated 

 with thunderstorms over the British Isles. The results of 

 the kite and balloon ascents carried out on May 19 have 

 not vet come to hand. 



