:356 TEANSACTIONS OF THE [mAY 17, 



I ought not to dismiss the subject of comets witliout at least 

 nlludiug to tlie numerous unprecedented and interesting ])he- 

 nomena presented by tlie great comet of 1882: First, its unques- 

 tionable relation to, but distinctness from, its predecessors of 

 1880, 1843, and 1668, the three belonging to one broth- 

 erhood, of common origin, and all following nearl}' the same 

 path around the sun. 1 call special attention to this point be- 

 cause Miss Gierke, in her new and admirable " History of Astron- 

 omy in the Nineteenth Century" (which I ho})e every one inter- 

 ested in astronomy will read as soon as may be) has, I think, 

 made a mistake regarding it, assigning to the difference between 

 tlie computed periods of these comets much too great an impor- 

 tance. 



The strange elongation of the nucleus of this comet into a 

 string of luminous pearls; the faint, straight-edged beam of 

 light that enveloped and accompanied the comet for some time; 

 and the several detached wisps of attendant nebulosity that were 

 seen by several observers, are all important and novel items of 

 cometary history. 



Meteors. 



Time will not allow any full discussion of the progress of me- 

 teoric astronomy. It must suffice to say that the whole course 

 of things has been to give increased certainty to our newly ac- 

 quired knowledge of the connection between meteor-swarms 

 and comets, and to make it more than probable that a meteor- 

 swarm is the result of the disintegration and breaking u]) of a 

 comet. This seems to be the special lesson of the Bielids, the 

 reappearance of which as a brilliant star shower last November 

 attracted so much attention. In an important pajier read before 

 the National Academy of Sciences, last Ajn-il, Professor Newton 

 pointed out how all the facts connected with the division into 

 two of Biela's comet forty years ago, its subsequent movements 

 and disappearance, and the meteoric showers of 1872, and 1885, 

 and especially the pe;'uliar features of this last shower, all con- 

 spire to enforce this doctrine. 



I mention, doubtfully, in this same connection the recent sup- 

 posed discovery by Denning of what are generally alluded to as 

 ''long radiants:" systems of meteors, i. e., whicli for weeks, 

 and even months together, seem nightly to emanate from the 

 same point in the sky. One of these radiants, for instance, tlie 

 first of half a dozen described by Mr. Denning, is about l^'' 

 north of ft Trianguli, and the shower appears to last from July 

 to November, at the rate of i)ei-haps one or two an hour. 



If the fact is real, it follows inevitably that, disseminated 

 through all the space in which the earth is moving, and lias 



