the Meteor of February 11, 1850. 261 



'' It is necessary to say how these altitudes and azimuths 

 are obtained. 



" Placing myself nearly in the position I was in when I saw 

 the meteor, I took the altitude and azimuth of the place I be- 

 lieve it to have occupied on the windows by instruments. 



" The place of this meteor could not be taken, as is usual 

 with meteors, by noticing what stars it was near, for its bright- 

 ness obliterated all, even Jupiter. I estimated its position 

 with respect to a Leonis, Jupiter and « Hydrae, by looking, 

 directly it was dark again, in the right direction as nearly as 

 I could ; and I have also estimated it since by noticing the 

 sun, moon and Jupiter when they have occupied nearly the 

 same position on my window. 



" It may be worth while to say what is the extent to which 

 error in the position is probable. 



*' The meteor certainly entered my field of view at the alti- 

 tude 40°, that of the top of the window ; and its end was at 

 the altitude of about 25°. It is quite certain it was more than 

 20°, and nearly certain that it was not more than 25°. 



"The altitude which is most important is the bursting- 

 point. 



"30°* is the altitude at which the bodies were first per- 

 ceived to be separate ; there is little doubt here ; the error 

 could not exceed 3° each way. 



'* But as no change was perceived in the motion of the me- 

 teor at the time of bursting, either in velocity or direction, it 

 is probable that it divided 2° or 3° higher than when it was 

 perceived to consist of about six bodies. 



" These bodies spread very little laterally. They appeared 

 to divide, by the apparent motion of some being quicker than 

 that of others. 



" There can be little error in saying that no motion in azi- 

 muth was perceived, for the perpendicular divisions of the 

 window would guide the eye, 



"The azimuth is less important than the altitude; this 

 is fortunate, since the probability of error in azimuth is greater 

 than in altitude ; for a little variation in the position of a body 

 at 30° elevation makes a great variation in the azimuth, and 

 also the certainty of a few inches in the place where I stood, 

 affects the azimuth, but not the altitude. I think however it 

 could not be at a greater distance from the true S. than 40° 

 or less than S5°" 



• The accounts from Castle Donnington were received shortly before 

 this paper was prepared for the press, and therefore have scarcely influenced 

 me in the following discussion of the results. The altitudes seem to be too 

 high. I have requested them to be remeasured, but I have not received 

 any further information at the time of sending the MSS. away. 



