01 SHOOTING STARS. 



BY II. A. NEWTON. 



The periodical shooting stars, particularly those of August and November, have hitherto 

 very naturally attracted more attention than the sporadic ones, those which are seen on every 

 clear night in the year. Yet these latter are objects of no small interest. There are methods 

 of observing, and of computation, by which much can be learned about them, and observations 

 already made show something of their numbers and of their -place in the solar system. I 

 propose, to combine these existing materials and see to what they lead us. If it be said that 

 I use rude processes and inexact data, and reject in computing terms of considerable 

 importance, I must plead that it is a step forward to do anything in this direction, and express 

 the hope that better data will soon warrant the use of more refined processes. 



It will be necessary to assume some propositions which are probably not strictly true, and 

 others which may not be universally conceded. I shall, however, set forth very distinctly 

 these assumptions that future observation may correct them if erroneous, and verify them if 

 true. 



In the American Journal of Science for July, 18G4, p. 135, I gave a table of the computed 

 altitudes of three hundred and forty-two shooting stars, which are all I have been able to 

 collect from the scientific journals.* The altitude is in each cg,ge computed from the parallax 

 shown by observations made at two or more places at some distance from each other. These 

 observations are always subject to large probable errors, and there is often great doubt 

 whether different observers saw the same object. An attempt is made to separate in the 

 table the manifestly unreliable cases from the rest. But the remaining ones individually are 

 not all deserving of confidence. Taken together, however, many of the errors will balance, 

 and the whole may be made the basis of computation as a first approximation. 



DISTRIBUTION VERTICALLY OF THE MIDDLE POINTS OF THE LUMINOUS PORTIONS OF THE 



METEOR-PATHS. * 



When in the table the altitudes of the beginning and ending of the visible part of a path 

 are given* the half sum is taken as the altitude of the middle point. When only one end is 

 given we might reject it altogether. It seems better, however, to give some weight to such 

 determinations. By adding or substracting one-half the average descent of shooting stars wo 



— ' — ■ ' ' w ~ 



"This table, with the accompanying notes, is given in an appendix to this memoir. 



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