202 Mr. J. N. Lockyer. On the Classification [Jan. 10, 



There are no further observations which might enable us to further 

 trace the sequence of spectroscopical phenomena in the comet at this 

 return. 



At the next return, however (perihelion passage March 30, 1879), 

 several observations were made on different dates. Low temperature 

 carbon bands were recorded 011 25th March, 1879.* Bredichinf made 

 a series of observations, extending from 26th March to 2nd April, 

 bat only gives one set of wave-lengths, as if no change had occurred 

 in the spectrum of the comet during the interval. The observations, 

 however, seem to indicate hot carbon with manganese absorption. 



An observation was made two days after perihelion by Young, J 

 who observed bands near 476 and 560, and measured one at 512. 

 These are probably hot carbon bands with manganese absorption ; in 

 the case of the green band at 512, the first maximum of the fluting 

 at 517 was probably masked in the way I have already explained, so that 

 the second maximum at 513 was the brighter. On April 17, the Astro- 

 nomer Royal observed cool carbon bands in the comet's spectrum. 



Messrs. Copeland and Lohse|| observed the comet from April 16 to 

 May 2, and give 547' 6, 515'6, 469'6 as the wave-lengths of three 

 bands. Of the band at 547'6 they say, " it was very ill defined on 

 both sides, and being without any definite brighter part, its wave- 

 length is very uncertain." The measurements made on April 16 are 

 not given separately, nor is it definitely stated that any measurements 

 were made on that day. The apparent discrepancy of hot carbon 

 being seen when the comet was further from perihelion than when 

 cool carbon was seen, is most probably another case of a comet tem- 

 porarily passing through a meteoric swarm, and thereby increasing 

 in temperature, as was the case with Comet Wells, 1882, on May 20th. 



Winnecke's Comet in 1877. 



Winnecke's Comet, 1877, was observed by Lord Lindsay^" on 

 April 18th, a day after perihelion. Its spectrum presented much the 

 same characteristics as in 1868. Bands at 472'2, 516, and another 

 near 556 were observed. The strongest was at 516 and the band at 

 556 is given as very weak. 



We, no doubt, have here another case of manganese absorption 

 occurring in conjunction with hot carbon radiation, when a comet is 

 near perihelion. On May 5th, the spectrum of the comet gave every 

 indication of hot carbon in conjunction with manganese radiation, the 



* C. Konkoly, ' Astr. Nackr.,' No. 2269. 



t ' Astr. Nachr.,' No. 2257. 



' Amer. Journ.,' TO!. 17. 



' Monthly Notices,' vol. 39, p. 429. 



|| ' Monthly Notices,' vol. 39, p. 430. 



^[ ' Monthly Notices,' vol. 37, p. 430. 



