On the Meteors of 13th November, 1833. 147 



the two foregoing results, which gives 2263J miles, as the approxi- 

 mate place of the radiant. 



This estimate is entitled to greater confidence from the fact that 

 according to the estimate of Hon. S. DeWitt, of Albany, (obligingly 



communicated to the writer,) the height estimated from the observa- 

 tions of Capt. Parker in the Gulf of Mexico, compared with those 

 made at New Haven, is 2027 miles, differing less than one ninth part 

 of the whole from the estimate made from the three other observa- 

 tions combined. 



That this is an approximation to the truth, may be farther infer- 

 red from the correspondence of these estimates to one founded on 

 the data of Prof. Thomson, (see p. 138,) which gives the perpendicu- 

 lar height above the earth's surface 2424 miles. Finally, taking the 

 mean of all the foregoing estimates, we obtain 2238 miles, as the 

 nearest approximation we are at present able to make to the perpen- 

 dicular height of the source of the meteors, above the surface of the 

 earth.* 



3. The meteors fell towards the earth, being attracted to it by the 

 force of gravity. 



It seems unnecessary to assign any other cause for the descent of 

 these bodies to the earth, than gravity, a known and an adequate 

 cause. It is easy to conceive, that bodies situated in space at a dis- 

 tance from the center of the earth comparatively so small, as about 

 six thousand miles, would be brought under the dominion of the 

 earth's attraction, whatever may have been their previous tendency 

 towards one another, or towards a central nucleus. Such a tendency 

 indeed, if it existed, we shall hereafter see reason to believe was very 

 slight, and would not materially oppose terrestrial gravitation. 



fell 



considerable 



with each other. 



The courses are inferred to have been in straight lines, because 

 no others could have appeared to spectators in different situations, to 

 have described arcs of great circles. In order to be projected into 

 the arc of a great circle, the line of descent must be in a plane pass- 



# I know of no way of accounting for the want of a parallax in R. A. correspond- 

 ding to that in Dec. (as might be expected in some of the observations,) except to 

 ascribe it to an uncertainty in respect to time, which would obviously greatly affect 

 the observations in R. A. 



