432 



NATURE 



[August 2 2, 1878 



be solid enough to sweep all before it. It was noticed on 

 the air and on the very buttresses of the Peak that the 

 boundary of the shadow was strongly coloured in the 

 prismatic order. The wide extent of Alcali Plains round 

 Separation and Preston — plains broken by nothing save 

 the wonderful avenue of telegraph poles along the railway, 

 and the solitary water tank and telegraph operator's house, 

 enabled these and the associated phenomena to be seen 

 well there also, and there were just sufficient clouds 

 above the eastern horizon to bring out into strong relief 

 the retreat of the shadow through the air, while during 

 the eclipse the leaden light on the desolate plains gave 

 rise to an intense feeling of loneliness and weirdness. 

 The daring genius of Edison has left its mark on this 

 eclipse. So soon as he had completed his tasimeter he 

 saw its applicability to eclipse work in determining the 

 presence of heat waves in the radiation from the corona. 

 I had the rare privilege of seeing the great inventor at 

 work gradually increasing the sensitiveness of his won- 

 derful instrument with the most consummate knowledge 

 of principles and contempt for elaboration, until at length 

 during the eclipse he was rewarded by seeing the speck 

 of light on the attached Thomson galvanometer give a 

 decided swing from its zero on the dark moon when the 

 image of the corona was brought on the fine slit in the 

 plate which shielded the tasimeter from its surroundings. 

 The instrument was too new to succeed in other hands, 

 even those of Prof. Young ; but he was not to be beaten. 

 Driven from one instrument he took up another — the 

 thermo-electric pile — and was rewarded by finding a heat 

 line in the ulti;a-red. This opens out another new line 

 of work in future eclipses ; and so science advances. 

 Rumour here says that one distinguished astronomer re- 

 mained away because he considered eclipses " played 

 out." What a lesson he has learned ere this touching 

 the need of that receptivity to which I referred in my 

 former letter ! 



Mindful of your space I must here conclude my state- 

 ment of the more salient solar phenomena observed, the 

 detailed discussion of which will occupy the astronomical 

 world for some time to come. I shall have been very 

 unfortunate and unworthy of my post if I have not suc- 

 ceeded in convincing your readers that several important 

 advances have been made, and that the work done on 

 the eclipse of 1878 will rank high in astronomical re- 

 cords. I have not yet, however, quite finished the story 

 I have to tell. Students of solar physics may congratu- 

 late themselves that the gravitational astronomers will in 

 the future insist upon having their finger in the eclipse 

 pie. In my telegram I was enabled to announce the 

 position of the body observed by Prof. Watson near the 

 sun. Since the telegram was dispatched the matter has 

 been seriously discussed by Prof. Holden and others, and 

 little doubt remains that a new major planet has been 

 discovered, if, indeed, Vulcan has not been refound. 

 Prof. Watson's work has been acknowledged on all hands 

 to be a veritable tour de force. The Naval Observatory 

 instructions contained a map of all stars near the sun 

 down to the serenth magnitude. Prof. Watson deter- 

 mined to review all these, and provided his equatorial 

 with paper circles on which to mark the difference of 

 right ascension and declination between any body not 

 marked on the chart and the sun. After the eclipse, and 

 before the instrument was dismounted, Prof. Newcomb 

 and Mr. Lockyer saw the precious record in situ. It was 

 here at Manitou that Prof. Watson again reviewed his 

 work, and despatched a telegram to the Smithsonian 

 Institution corroborating the one I had previously sent to 

 you. 



The English observers are full of appreciation of the 

 reception they have met with from their American con- 

 freres. Prof. Thorpe and Dr. Schuster were the guests of 

 Prof. Hall's party at Las Animas. Mr. Lockyer, invited 

 by General Myer to Pike's Peak, by Dr. Draper to 



Rawlings, Prof. Newcomb to Separation, and Prof. 

 Wright to Las Animas, decided for Rawlings, where Dr. 

 Draper placed all the resources of his observatory at his 

 disposal. A thing unknown in England — that is, a tra- 

 velling railway photographic car- -being, however, placed 

 at the disposal of the astronomers by its proprietor, Mr. 

 Silvis, it was decided at the last moment to establish 

 another station, and on the morning of the eclipse Prof. 

 Watson and Mr. Lockyer proceeded to Separation, a 

 station on the Union Pacific Railway, between the eclipse 

 camps there and at Preston. 



The Times correspondent, writing from Pueblo, South 

 Colorado, July 31, states that Dr. Schuster brought 

 out with him a couple of fluorescent eye-pieces, -vt-ith a 

 view of re-determining the position of the lines he ob- 

 served in 1875 ; b'^t a too-confiding faith in the tender 

 mercies of the baggage-men in charge of the instruments 

 led to the utter destruction of one of the eye-pieces, while 

 the other was so injured that it was impossible to get it 

 into order in time for the eclipse. Indeed, nearly all the 

 instruments, in spite of most careful packing, suffered 

 more or less damage, either during their canter — for such 

 it can only be called — along the Western railroads, or at 

 the hands of the " baggage-smashers " who took charge 

 of them at the depots. The baggage arrangements of 

 American railroads are doubtless perfect in theory ; but 

 the practical application of them is simply ruinous to 

 scientific apparatus. 



The newspapers are filled with allusions to the pheno- 

 menon ; its effect on animals, on the colours of objects, 

 and on their visibility, was noted everywhere. The dark- 

 ness was far from being so great as was anticipated ; the 

 decrease of temperature was, however, very considerable. 

 At La Junta it fell from 96° to 80° ; at the time of last 

 contact it had again risen to 93°. In Pueblo the fall was 

 as great as 23^° — i.e., from 103° to 79*5°. 



The following interesting and amusing account of the 

 eclipse observations of Prof. Lewis Swift, by a reporter of 

 the Rochester Democrat, appears in the New York 

 Tribune. 



Prof. Lewis Swift returned from Denver, Col., Sa- 

 turday evening, bringing splendid trophies' of his skill 

 as a searcher of the heavens. That his discovery was 

 not duly reported by the Associated Press is chiefly 

 owing to Prof. Swift's modesty in heralding the results of 

 his labours and his desire to carefully determine the 

 significance of his observations before making public 

 announcement. Yesterday afternoon we visited Prof, 

 Swift at his pleasant home in Ambrose Street, and learnt 

 from him the story of his visit to Denver and observa- 

 tions of the total eclipse. Prof. Swift said : — " Up to 

 the time of the eclipse the prospects for a clear day were 

 very poor. The nights were clear, but it was cloudy, and 

 rainy every afternoon. Sunday afternoon theretwas 

 a clearing storm, with hail and drenching rain. Up to 

 Sunday afternoon an unprecedented amount of rain had 

 fallen in the region. On Monday morning there was not 

 a cloud in the sky, and all predicted a clear day, and we 

 had it. The final preparations were made as rapidly as 

 possible. A. C. Thomas had arrived at the eleventh hour 

 from Chicago with a telescope and spectroscope attach- 

 ment. Prof. Hough had brought a small telescope with 

 fine lines stretched across the object-glass, and a micro- 

 meter eyepiece, for the purpose of measuring the corona. 

 I had secured from the Mayor the services of a police- 

 officer to keep the grounds about the instruments clear 

 from spectators. According to Washington predictions 

 the eclipse was to commence at 4h. 7m. 5o'4s, Accord- 

 ing to Prof. Colbert's calculations it would begin at 4h. 

 lom. 50s,, Washington time— a difference of three minutes. 

 Prof. Colbert's prediction, was proved to be very nearly 

 correct. About half an hour before the eclipse was to 



