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Show Jp H"F New Facts About tke Element Coronium tke - iBSHy Blood-Red Streamers 2 Million Miles Long, the 'llS y; Coronal Arches and Other Wonders of the gj ''l' " 'y Sun's Corona Observed at the Last Total Eclipse 'j The Sun' Corona, Showing Elf 2?y 8a6eZ . Lewis, tive Prominences, Photofrapbed Of the Nautical Aimanach Office, United , During the Total Eclipse Ot States Naval Observatory, Washington June 918, at Greta OBSERVATIONS of the total eclipse River, Wyoming, by the j of the sun that was risible in the ,.. "TSJjjpg5-- "' ' , '"''' E x p e c ; i o n of the United States on the eighth of last ' " ' obyervatorT June have yielded results that will be of , -fj"' -' 'M great value to science. A large number of ' J excellent photograpntc and spectroscopic .... v , apparently between fl records of the solar corona, that is visible ' (MVfiSs iaSSSL - -a TF mFJFfjt&t uCHmls S a-v Q;xtv thousand lBBnnnnl only during the brief moments of a total ', ; v 'na '' , 77T,,, ,TBiWe1 eclipse of the sun, were obtained by nearly fif iifSs ' ,hou5b their actual aU of the eclipse expeditions that were sta- ' f f ; J B , T"" k "T nV ,he! i tloned along the path of totality In the ' ' i tl foreshortening. Ce of the- western States from Washington to - of some - -A Kansas. , It 19 expected that the information de- V rived from careful future examinations of ' these records will material assist in nd- L ' ; r " ; . vancing our knowledge of the nature of lt Wa: ;;ll?refore extremely c::t. J .. j lt.- 1 - ' 1 ' 1 ' 1 ' " ' " " ... -J M-nflr bHB rJ The Sun's Corona, Showing Eftf tive Prominences, PhotogiaiW During the Total Eclipse ot June 8. 1918, at Green R ver. Wyoming, by the ' Expedition of the Yerkes Observatory average height. The two most ejM sand and sixty thousand miles "" though their act ual height W h! v creator owing to the N shortening. 0e of these 6 " pecu ur r inj ' - - ark -'"- so huge that two or three pUr of the earth cc be jged - "' -;Ti :: .1:5: - ' " '' ' -. . . - Astronomical Photographer Throwing an Imago of the Sun Into n Camera 100 Feel in Length. By Isabel M. Lewis, Of the Nautical Almanach Office, United States Naval Observatory, Washington OBSERVATIONS of the total eclipse of the sun that was visible in the United States on the eighth of last-June last-June have yielded results that will be of great vaiue to science. A large number of excellent photographic and spectroscopic records of the solar corona, that is visible only during the brief moments of a total eclipse of the sun, were obtained by nearly all of the eclipse expeditions that were stationed sta-tioned along the path of totality In the western States from Washington to Kansas. It is expected that the information derived de-rived from careful future examinations of these records will materially assist in advancing ad-vancing our knowledge of the nature of the solar radiations and the connections existing between the sun spot cycle of solar activity and all the attendant, complicated compli-cated phenomena of the upper solar atmosphere, at-mosphere, as well as the resulting changes tn the earth's magnetism and weather conditions. con-ditions. On nearly every clear day for several weeks preceding the eventful day of the eclipse sun spot groups were to be seen on the surface of the sun. The period ot maximum solar activity for this cycle was passed only a year or so ago. and as the decline toward the period of minimum activity ac-tivity several years hence is very gradual lt was predicted that the light of that mysterious halo of the sun, the corona, would be unusually brilliant. This prediction predic-tion was fulfilled, for the corona, visible during the eclipse of June 8, will go down Into eclipse history as one of the most brilliant and Interesting in Its complicated structure of any of the eclipses of recent years. Prints from original negatives unfortunately unfortu-nately fall utterly to convey to us any idea ofthemagiilficop.ee 0f the coronal structure, while the exquisite pearly radiance of Its Irght, described by observers of this eclipse as bluish-white, is but a. cherished memory to those who were fortunate enough to observe ob-serve It. To appreciate how 'omplex find Intricate in the structure of the corona one must go either to the original negatives that are full of detail, to photographic copies on glass or drawings from the original orig-inal negative. No adequate method for reproducing the corona! structure on prints tias yet been devised. The accompanying drawing at the corona made by Edison Petllt from negatives obtained at Mathc. son. Col., glve. us what the photographic print cannot, give an excellent Idea of the complicated structure of the corona. It must be left, to the painter to convey to the mind the superb Coloring, the. con traitlng effect of the blood-red prominences. promi-nences. lh.it wre so conspicuous In this eclipse, with the grayish tinged dink of the occulting noon, the orange tinged chromosphere chromo-sphere a'l the pearly light Ot 'he coronal streamers Interlaced 'o form the petals of ome dowers gorgeous beyond description fjr curved Into a series -if gothlo arches loping the rnu-i conspicuous prom! nence and towering to n height of more than two hundred it,,,,.:, id rnllfl( shove fh' aurface "( lire in. Drawing of the Corona Made from Photographs Taken at Matheson, Colorado, Showing the Complicated Com-plicated Structure of the Corona. By Edison Pettit The corona of the June eclipse was very unsymmetrical. resembling a huge triangle tn form, with the base to the west of the sun and the apex to the east. It is of the mixed type. In which the more evenly developed de-veloped streamers to the west represent the type associated with maximum sun-spot sun-spot activity and the longpr equatorial streamers to the east the sunsnot minimum type, showing that the decline toward minimum min-imum solar activity for this cycle has already al-ready begun. The longest coronal streamers, those to the east, of the sun. It has been estimated, extend to a distance of fully three solar diameters, or over two and one-bslf million mil-lion miles. This distance Is not. unusual in fact, during certain eclipses streamers eight or nine million miles In extent have been observed. The petal formation so notlceahlo In this eclipse has also been noted In certain past eclipses, particularly-1n particularly-1n the Indian eclipse of 1S98. Mont of the petal-forming streamers seem to originate near the limits of the sun"pol 7,one. while those over the solar poles are straight The arching of the coronal rays over all the most. Important prominences Is considered con-sidered to be very significant, lt has also been observed In several past eclipse., and there seerns llltlo doubt now that, the sunie forces In the sun that produced the eruc-iivc eruc-iivc prominences were also responnlhte for the arches above, them. It In prohnhln that, the coronal streamers are largely electrical ID their origin, lust, as the auroral streamers stream-ers of the earth's upper atmosphere a.ro electrical pbehotneni EOrtdence Is also forlhmnlrig frrtn the June eclipse to strengthen the view that condensed metallic vapors are projected to distances of several million fnlle from the solar surface far beyond the Hnilt". reached by the prominence whose, aver age. height. Is from flftv thousand to one hundred thousand miles, though helfhtH of over three hundred thousand inlh- Itn.' e heen attained hv certain spectacular prom loeoces the Hrrhl of the I(i,k , orotie, II ll eclipse, belongs to the unknown element coronium. It is strongly suspected that this is cot the only line of this element, though It is the most intense one. It is believed that there are at least two or three fainter lines belonging to this element In the violet end of the spectrum. It is also believed that there may be two of three more unknown elements that are true coronal elements, occurring, however, less generally than coronium. It is not likely that all of the fourteen or more bright lines of unknown origin that have been observed in the corona belong to the element coronium. H is believed by certain cer-tain scientists that the coronal, lines rep. resent some form of matter electrically excited. Knowing the accurate wave length of coronium. It. may be possible to Identify It by laboratory experiments with some element existing on the earth. Just as llamsay. In 1S95. discovered helium In the mineral clevlte long after It had been discovered in the atmosphere of the sun. According to spectroscopic obeervaUoni recorded on June J, showing the dlltrtbo tlon of coronium around the sun. as well ns several of the most characteristic gases or the prominences, this element is very Irreeularly distributed In the solar atmosphere, atmos-phere, It occurred In greatest abundance In the SUn SPQt gone, was observed to ft Considerable extent in the vicinity of the south solnr pole, but was entirely absent la the neighborhood or the north pole ot the sun. Moreover, Its distribution was entirely Independent of the element be-longlng be-longlng to the prominences, thus showing that there Is DO necessary connection lie tween the lolar prominences and the element ele-ment coronium. a most spent teuUr feature of the icltpe was the magnlfloenl solar prominence. t apped with sharply curved coronal arches' To the astronomer observe, tltmi of the prominences during totality bit not now Considered of great Importance, since It has beD possible for some lime to studv these products of the ceaseless solnr ac llvlty on any clear day by means of Milt- nhie spectroscopic Instrument Their aseootatton With the coronal arcbe In this eclipse, ns well u . ' lain prevtOUl eclipses. Is Important, since M7 tad to a better understanding or the nature and underlying reuse of the peculiar ,-oronnl stremners n, nrOfll "'". - observed In this Mips .,,, eruptive prominences j ' v-i- '"-::':::r' - ' form within a very few i The accot ring rhotogt" are always . -- ;vei. and going U suit ot jl only the frequency of tMiH d cet fob) the and many all:.-.' ' ' a notnena maj unravel the secret "Tjji '' ,eHj some crcat underlying force ,tht P" periodical!.! through the sun's '-"'"j) It is still ear'y to consider the cJ3 osr.' , - ,- ,- 'lipsf ! JJSj the astronomers '-. observed ij busily oiv :-.": -c with sstron ,, r.i.,r, tni:i,,v ",0 oPtV ' "'tT W extensively the c.-.-nls obtained. JJS vet 1 !- ' S ""mV, eerxcrs !,. ie only preltw1'' j The total phase of '' ecUpJJ served with great sic.-c b the , .. .v . '';,,',.ll"',V- ,-. ' ;r - ,, ,.:'e.sor " ' ,u ,.; .. V, O', M'TVatOfJ. "ji ... ,;.. ,. most xalawMJI ' v !-..,:,, .hat ha eer " ''' ' ' "' '" ' 1 u '' 1 r ,K .- " :' N,,v YEiM '.s . I ,., epiMOOVlfttlO : . wl sand ,,,nv to t'cngrrss In ,"'" ' . tttts ,-,-iipse, t vnluablo results t Uakgr, is kc-j ob-et ator itio-ri-teJ l'o cr. " " vjj! ami the ' ' i ,. , : i thm 'j, value ncie iud -t Mnt'iseeai ere alse i tleM here Pi te g3 lie te . -'led I (he Mpe i-.iiod IH been found from a prellmlnarv stndv of the SpeCtOgram taken on .tunc S. consists Ohlefll of Intetiso conllnuoun nvdlgtlonii That the light of the Inner enrnua Is not. due to reflected sunlight to any great ex lent. Is shown from Urn fact that the dark absorption lines of the normal solnr 'speo-trumi 'speo-trumi were absent. BUY bright lines were seen clearly, and their wave lengths have been meevaured. Including the Important green line of the unknown element oor-odium, oor-odium, Tim existence of seven additional bright linen wan suspected, hut these won1 ex iremely faint The corona, has shOWU In severnl recent eclipses as many an fourteen four-teen bright line very plainly The comparative com-parative falntneM of the line In tbe corona cor-ona observed In .luno hi believed to he duo to I In- feci thai the solar activity was very gre.it nt thin lime. As a result, more than the usual amount of solsr matter was being ejected front the surface of the iun Into the inner corona ss well a Into the , hxomoephere, the lower solar atmosphere riii- produced Lhe unueual general brll Pep ! 1 " Pf llancy of the corona and the relative fnlpt-ness fnlpt-ness of the true coronal lines. Though the charadterlltio lines of t'hp corona wero btflOW the average In numher and Intensity, Inten-sity, sconin of bright line belonging to the gases of the prominences were re corded. II will he possible to obtain from Ihe observations of Ihls eclipse very accurate mensiirnineiils of the green line of corn nlnin. Prcllmin.'irv tngMUfOmetftl of this line place ii at wave length 58(08 Instead of 6817, the value that was held for so many year, and therefore confirms Ihe results obtained h.v Professor W. W. Osmp-hell Osmp-hell and Other In more recent years The location of Ihls line In Ihe spectrum It' of the greatest Imporlance II useless to expect, to Identify the element coronium until It wave length In known with a . high degree- of accuracy. It Is one of lh first laws of spectrum analysis Itint every chemical element ban its own character Intle line 01 Ri-oup of linen In the spectrum rue green line of the spectrum al wave length e.tn.t, mo rat seen only during lolal lirr.it rilll.iln nlclil.i Itenervsil, |
