On the Meteors of 13th November, 1833. 333 



paring Prof. Olmsted's observations with Prof. Thompson's — made at 

 a distance from it of 16° of longitude, while there ought to be, on the 

 supposition of parallax, a difference of A.R amounting to 25° at least, 

 there is in fact a difference only so great as might be accounted for 

 by indefiniteness of observation ; and that difference, such as it is, in 

 the direction opposite to parallax. Again, in consequence of the move- 

 ment of the earth on its axis, the observers themselves, who noticed 

 the fixed position of the radiant, changed place, during the period of 

 their observations, 15°, 20° and, in one case (that of Prof. Aikin) 

 30° of longitude j and the absence of a large parallactic motion to the 

 west is only to be accounted for either by the absence of parallax or 

 by a supposed easterly motion of the meteoric magazine, so to call it, 

 just keeping pace with the earth's revolution. The latter supposi- 

 tion is astronomically untenable except at a distance which would not 

 account for more than one tenth of the parallax observed. We are 

 compelled therefore by these two equally decisive circumstances- 

 namely the absence of both 'parallax and parallactic motion, to ap- 

 ply elsewhere for a solution of the apparent progressive augmenta- 

 tion of north declination as the observer's place moves southward. 



k 



It is worthy of remark that if we investigate, by means of the da- 

 ta furnished in the table, the parallel in which the radiant was verti- 

 cal when on the meridian, we shall find it to be that of lat. 34° N. ; 

 and in like manner we shall find that in lat. 3° N. the radiant would 

 lie in the northern horizon ; and that, in lat. 65° N., it would lie in 

 the southern horizon : beyond these two parallels therefore, of 3° 

 N. and 65° N., it would seem that the meteors could not be visible. 

 Additional observations upon the radiant are highly desirable ; and it 

 is hoped, even now, that such persons as may have it in their pow- 

 er to collect and give them to the public will not fail to improve 

 the opportunity, — particularly persons far to the south, or west. 



The statements of Capt. Parker of the ship Junior, which have 

 been alluded to already, deserve a special notice. Capt. P. it will 

 be remembered being in the gulf of Mexico, lat. 26° N. Ion. 85J° 

 W., saw the meteors confined to a small space of action, and the ra- 

 diant, at 3 o'clock, in the due N. E. 45° high ; the space of action 

 spread wider during an hour and a half, and the radiant rose 5° to 

 10° in the mean time, without however moving from the N. E. at 

 all, and about 5 o'clock the meteors spread over the whole heavens. 

 The analogy between these appearances and those which Humboldt 

 witnessed at Cumana in 1799 it striking. In that year while Mr. 



