76 



OBSERVATIONS OF COMET II. 1861. 



[13 



The determinations of N. P. D. from July 2 to July 9, inclusive, are 

 liable to some uncertainty, in consequence of the defective state of the 

 clamp by which the declination-rod was attached to the polar frame. The 

 determinations of R. A., however, are trustworthy. 



The R. A. and N. P. D. for July 2 are obtained by taking a mean 

 between the results of the comparisons with (e) and (d). 



It is probable that in the observation of Nov. 30 the recorded micro- 

 meter-reading was too great by 5 revolutions, and that the N. P. D. should 

 consequently be diminished by 5 r = 43""2. 



