322 Dr. A. A. Bambaut. On the Orbit of the Part of the 



The part of the stream through which the earth will pass this year 

 lies between the position of those meteors which the earth encountered 

 last year and that of the meteors of 1866. It is, therefore, of import- 

 ance to investigate how far the orbit of the meteors observed in 

 November, 1898, agrees with that deduced from the observations of 

 1866. 



Unfortunately the observations obtained in 1898 are fewer than 

 could be desired. Unfavourable weather prevailed almost universally 

 in England. On the Continent meteors were observed at a few stations, 

 but they appear to have been outlying members of the stream, and the 

 denser portion was not encountered until about 19 hrs. G.M.T., on the 

 morning of November 15 (civil time). For observations at the time 

 that the earth was passing through the densest part of the stream, we 

 are wholly dependent upon the American observers. The time of maxi- 

 mum display is, owing to the paucity of meteors, somewhat indefinite, 

 and seems to have differed by several hours at different stations. The 

 most reliable accounts, however, agree in placing it between 19 hrs, 

 30 min. and 22 hrs. G.M.T. on the morning of the 15th, and from a 

 discussion of all the separate determinations, I have been led to adopt 

 20 hrs. 45 min. as the most probable time of maximum. This agrees 

 exactly with Professor Young's result, who writes, " The maximum 

 was about 3 hrs. 45 min. (Eastern Standard Time) when for about 

 20 minutes the meteors averaged two or three a minute."* 



In Table I are given — the name of the observer, his observatory or 

 station, its longitude and latitude, the Greenwich time, and the K.A, 

 and declination of the radiant point. 



In this connection I may remark that in order to contribute to an 

 accurate determination of the orbit, the G.M.T. corresponding to the 

 observation, and the approximate position of the observer are just as 

 essential as the co-ordinates of the radiant itself. In several of the 

 accounts before us I have had to assume that the position of the 

 radiant corresponds to the time given as that of maximum display, or 

 to the middle of the time over which the watch extended. 



The longitudes and latitudes of the observers' positions may also 

 in some cases be in error to the extent of several minutes, but they are 

 sufficiently exact to enable me to compute the " zenith-attraction." 



In Table I, I have included only those observations which seem to 

 relate to meteors belonging to the dense, or central, part of the stream. 

 They are all contained in the interval between 18 hrs. 58 min. and 

 23 hrs. 2 min. G.M.T. 



Each of these separate results has to be corrected for the influence 

 of the earth's attraction on the paths of the meteors during their 

 approach, and for the influence of the earth's motion on the apparent 

 position of the radiant. 



* ' The Observatory,' December, 1898, p. 459. 



