— 232 On the Meteor of May 18th, 1838, &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, Brandes, 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 Vol. xxvm 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. Sum 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.-xxv1 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 
ooting stars is very various, yet it appears that not unfrequently 
pers fis 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. 1 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 dintiictes of one mile, than that they should 
—— ‘witha diameter of a hundred feet, or even of a single foot. 
