366 



REPORT 1867. 



error of pointing, as already explained. Tlie altitudes and azimuths of the stars 

 •were calculated _ by the same formulae, and are placed iu the foreg-oing Table, to- 

 gether with their altitudes and azimuths calculated from their known R. A. and 

 N. P. D., iu order to give the means of judging of the degree of accuracy to be 

 ascribed to the observations. (The latter are put in braclcets.) 



I made au observation of the mean of the positions of tv^^o stationary meteors 

 (No. 60) soon after the clouds h.ad cleared oti, and before counting from" the chro- 

 nometer Iiad recommenced. The time was taken roughly by my watch, -w^hicli 

 was found by subsequent comparison to be seveii minutes slower than the chro- 

 nometer. The recorded time, 1'' 20'", takes into accoimt this difference. The 

 time of observing Regidus (No. 51) was not noted ; but as this observation fol- 

 lowed immediately after No. 50, it was conjectured from other similar cases that 

 the interval between them v/as about one ininute. Tlie times for Nos. 50 and 51 

 are, consequently, quite uncertain ; but as the place of Regulus, calculated from 

 the obsen-ation, agrees well enough with its true place, it is not likely tliat they 

 are much in error. By calculation of the E. A. and Decl. of the mean stationary 

 point from the azimuth 83° 24' and the altitude 25° 12', it is found that the R. A. 

 = 150" 58', and Decl. = +23° 36'. 



Soon after 

 reference to neignDourmg stars, by mappmg 

 on a piece of paper, from which the annexed diagram 

 has been transferred by punctures through tlie paper. 

 (It should be observed that the two meteors had about 

 the same altitude, and the more northward one was 

 much fainter than the other.) 



By making use of the star-map in Johnston's ' Atlas 

 of Astronomy,' I estimated the place of the meteors 

 to bs R. A. = 148° 45', and Decl. =22° 50'. The date 

 of the map being 1850, if allowance be made for an- 

 nual variations, the place for 1867-0 will be R. A. = 

 148' 59', Decl. =22^ 47'. 



This determination I consider to be more trust- 

 worthy than the other, the R. A. of the former being 

 probably too much in excess of that of Regulus. If 

 double weight be given to the second determination 



of R. A., and equal vreiglits be given to the declinations, the radiant point comes 

 out R. A. = 149° 39', Decl. = + 23' 12'. 



Cambridge, January 3rd, 1867. j. Chai.lis. 



^r seeing the .stationary meteor.", I noted down the mean position with 

 I neiglibouring stars, by mapping the stars and the estimated position 





f# 



e* 



n\ \ Mean posif.ion 

 ^ ( of thu meteor3. 



r* 



"1* 



%r RpqultlS 



Meteors, 1866, November 13th to 14th. 



Nov. 13th, 14'' 10'". 



Sid. T., 11 slow .34-26 

 Daily lo.sing rate=: 1-68 



Hourly rate of Chronometer= — 0"-09. 



