233 On the Meteor of May 18th, 1838, c^-c. 



of the course. The sum of the heights of 17 meteors at their 

 disappearance was 973 English miles. The sum of the heights 

 of 4 meteors at their origin was 199 miles ; sum of the lengths of 

 their paths, 162 miles. In 1823, Brandos, being then Professor 

 at Breslau, resumed his observations in concert with a number of 

 others, about twenty in all. A summary of their observations is 

 given in Yol. xxviii of this Journal. The sum of the heights 

 of 54 meteors at their disappearance was, according to these ob- 

 servations, 2761 miles. Sum of the heights of 45 meteors at ori- 

 gin, 2998 miles. Smn of 37 paths was 1619 miles. 



In December, 1834, Mr. A. C. Twining and myself undertook 

 a similar series of observations. We were not so successful as we 

 expected to be ; yet among the meteors observed, there were four 

 whose paths we were able to compute. The sum of their heights 

 at origin was 296 miles ; at termination, 216 miles, and the sum 

 of their paths, 142 miles. Finally, in Vol. xxvi of this Journal, 

 Mr. Twining has given for one meteor the height of origin 73 

 miles, of termination 29.5 miles, length of path 55 miles. We have 

 then, as the result of all these observations, the sum of the heights 

 of 76 meteors at termination, 3975 miles, being an average height 

 of 52 English miles. The sum of the heights of 54 meteors at 

 origin is 3566 miles, giving an average of 66 miles. The sum 

 of the paths of 46 meteors is 1977 miles, being an average of 43 

 miles. The average velocity of 13 meteors whose duration was 

 estimated with some care, is 22 miles per second, and the veloci- 

 ties range from 11 miles to 36 miles per second. The size of 

 shooting stars is very various, yet it appears that not unfrequently 

 they have a diameter of a hundred feet. 



From the preceding statements I think it will appear that the 

 meteor of May 18th did not differ essentially from the ordinary 

 shooting stars, with the exception of its magnitude. It appeared 

 at about the same height, moved with a velocity no greater than 

 is known sometimes to belong to common shooting stars, and ex- 

 hibited the usual phenomena of combustion. I see then no rea- 

 son for separating this meteor from the class of ordinary shooting 

 stars, any more than a large hail-stone should be considered a phe- 

 nomenon of a different kind from a small one. Shooting stars are 

 well known to be celestial bodies, that is, to have an origin for- 

 eign from the earth ; and it is no more strange that they should 

 sometimes have a diameter of one mile, than that they should 

 appear with a diameter of a hundred feet, or even of a single foot. 



