40 



ASTRONOMICAL PHENOMENA AND PROGRESS. 



the bud across tbe zenith WM quite as dis- 

 tinet as before. Mr. Hull thus .omments upon 

 the fact*: 



ICow, the** lw fact* go long way toward explain- 

 ing the aatar* of th* aodbeol licbt, and a few more 



that an D*oa*e*ry to do so aatUfaotonly ; but a* tbe 

 Ufht waa o vivid here, it muat have been *en In 

 irthar part* of the world, and a comparison of the 

 difrrrnt aimiBlila my bring about the denired re- 

 uk ; hMM* the** ***, and the following rough 



._ todlacal light ha* generally been *uppo*ed to 

 be a Icmlaoa* ring, surrounding the aun. and *it- 

 uated between tbe orbit* of Venn, and Man ; the 

 fact that the light ha* often been Men in both the 

 e*M sad w**t at th* sane place and time does not 

 aaVct th* probability of ihi. explanation, a* we have 

 only la swppaM th* earth tn he ju.t within the riot ; 

 bf* there are many difleultie* to enomnt-r, and the 

 xplautioa n*v*r eeemed aalia&etory. The initant, 

 however, th*t I *aw the prolonged ray, I felt aure 

 that Iks trdisitl light wa* aunllar in it* nature to 

 th* rays iaaued from a eoroet toward th* *un, which, 

 drifting over th* nocleui, an then forced backward 

 and form th* Uil ; and that, in the cane of tbe earth, 



the light la generated in thoaa region* to which the. 

 o U vertical, and, patting round the earth, the 

 la twept book in a direct line from the aun, 



thua f.-rraittg a train which alway* tend* toward a 

 potal in the heaven* 180* from the *un, and which 

 therefore rtaUonary with regard to the earth'* 



.- The Earl of Ro.e hM 

 prenUd to the Royal Society the results 

 of bit latest observations to determine the 

 araonnt of heat radiated from tbe moon. An 

 a'xtrart of the paper U given as follows : 

 "The observation* were first corrected for 

 change of the moon's distance from the place 

 of observation, and change of phase daring the 

 ooatinmsace of each night's work, and thus a 

 , wboee ordinal** represented the cale- 

 i (corrected) and whone absoisaie rep- 

 the corresponding altitudes, waa 

 fi>r each night's wurk. Ity roui- 

 Wntsjg all theae, a single curve and table fr 

 ivdorlng all the observations to the same 

 inlth-dlstanoe was obtained, which proved to 

 W neariy. bot not quite, the same as that 

 fMd by Prot 8*del for the liglit of tlu> stars. 

 n|.loying theUlilo thn <U-<liircd. and also 

 rloclg the heat-determinntiono ol.t:iin<-<l ,.n 

 the varions night* for change of ilixUn. 

 tbe n, a or*) accurate pha*e enrve waa ile- 

 de*4. Wkmting a more rapid Increase of the 

 radlaat beat on approaching full moon than 

 wan given by the formula prrvioimlx cmpl 

 Mt *i II I lot so nraeh a* Prof. Zollner's gives 

 '' moon's light. Hy employing Laplace's 

 Motion cf liglil in inir at- 

 , the heat -effect In term* of the scale- 

 was deded, aixl an approximation 

 to tb* height of the atmoepher* attempted. 



rmm a aerim of simnltaneon* meewnre- 



OMH of the moon'* heat and light at interval* 



iring b partial v1i' .'tnlier 14, 



when clnod* <lil not interfere. It waa 



foon.l that the heat and light dimlninh nearly 



If not qaitvpropnftkmsllv; the minimnm for 



bat* ocrwrrinjr at or *ry new the middle of 



tbe eclipse, when they wore reduced to about 

 half tlu-ir amounts before and after contact 

 with the penumbra." 



Jiiela'i Comet. Prof. Oppolzer has inves- 

 tigated the probabilities tliut the comet oli- 

 senred by Pogson at Mitdrus. lK-<-einl>er - and 

 8, 1878, was one of the fragments ot' I'.ieln's 

 comet, and is coiiviucv<l liv his eouipututiotis 

 that the likeness of the elements he obtained 

 to those of Hiela could not be the result of 

 chance. The comet seen by Pogson, it will be 

 remembered, was twelve weeks behind tlie 

 computed places of Kiel*. He made but two 

 observations of it, at about twenty-tonr-liour 

 intervals, and more places are n.-. >l. <l to give 

 the orbit of the comet. 1W. 11. A. Xewton, 

 of Cambridge, Mass., in reviewing the evidence, 

 ilevin- ii highly improbable that the fragim nN 

 ot' Hiela's comet have lost twelve weeks, as there 

 have been apparently no longer doubtful per- 

 turbations t hronch tin- lust ninety years. Jupi- 

 ter has kept at a considerable distuiin t'rom 

 them, and his influence has been allowed for. 

 The natural deduction is, as stated by Mr. Proc- 

 tor, that what Mr. 1'ogson saw was a meteoric 

 aggregation traveling in the track of the eomet, 

 but far behind it. In fact, it seems to be a 

 third piece of Uiela's original comet, separated 

 from the main body, perhaps, long ago. The. 

 size of the nucleus seen by Mr. Pogson was 

 comparable to that of the moon, allowing for 

 the probable distance of the comet. It took 

 over six hours to cross the dense part of the 

 meteor -stream on the 27th of November, 

 1878 ; and, had its thickness been equal to 

 that of the moon's diameter, the shower on 

 that occasion would have lasted ten minutes. 

 Prof. Newton conjectures that the meteors 

 seen on the evening of November 27th be- 

 longed to still another stream of fragment* 

 from Uiela's comet, since they were not seen in 

 so great numbers on the evening of the '.'".tli. 

 Possibly the Pogson comet belonged to that 

 stream. 



Mr. Daniel Kirk wood, of Bloominpton, Ind., 

 is of the opinion that several comets, moving 

 in nearly the same orbit as that of Bichi, 

 probably entered the solar s>*tei-i as n group, 

 and that, after making their first perihelion 

 passage in close proximity to each other, they 

 were, when receding from the sun. thrown 

 into their present orbits by the disturbing in- 

 fluence of jupitor. lie thus presents tlie case: 



1. Wat tb eonut of 1772 ijtnlirat ititli ftat nf JK- 



A&t The mean nf tlio novcn eonupciitivc' period* 



b*twen January 2, 1RO, and Scpti-mbrr 'ja. is.vj. \* 



,4*7.7 day*. C'unting five period* of tho name 



inran li'ni-tli fr"in Fcbnmry IT, 1772, tirinen u to 



i month* before tb* perihelion pa- 



( I* *!. In cither wnrd*. the menu |nTi<i ( l tu- 



177-' nml 1*0 wa grvtttfr by *liniit thirtv- 



evn dy thnn that bptwpim IWVt and 1M2. Tlio 



i during thr half-cent urv BH. 

 appariti'in of 177'i have not been computed. It 

 aeema very unlikrly, however, that the difference 

 .i,l r'.iiM thin he arc'Hintiol for. Wo con- 

 rlci.li>. thcreforr, th*t the cornet of 1772 wa not that 

 of Bicla. 



