18s Observations on two late Mefeors- 
matter. Or, let any one measure, in his mind, a distance of 
20 miles, and a duration of one second, and then let a globe, 
some portion of a mile in diameter, pass along the distance in 
that time, and through an atmosphere even of very diminish- 
ed density, it will not appear surprizing that, by the power of 
friction, the excitement of electricity, and the compression of 
air, it should surround itself and mark its course with flame- 
° 
In the present case the different Reprecentatsnns of magni- 
tude vary from 10’ to more than half adegree. If we place 
it at 15’, and consider that of the body 10’, we shall have 56 
rods, or one sixth of a mile, for the diameter of the meteor. 
The existence of these bodies in the form of revolving 
masses of matter is now generally admitted. That it should 
have been so long discredited by philosophical observers, and 
considered as embarrassed with difficulties, is perhaps an in- 
stance of the common fact, that the simplest theories are the 
last received. But though so near and so frequent in their 
appearance, they are probably the last with which, in many 
important respects, we shall be acquainted. Their pheno- 
mena and motions are too rapid and transient for the steady 
observation of science, and it is only from common observers 
at we can generally expect any account of them. _ Still, 
such accounts ought to be carefully collected, and such ob- 
servers to know that their opportunities may be made of use 
to philosophy. 
he circumstances which the observer should be prepared 
hese: 'The time of occurrence, the place of 
rise and of vanishing, and any points of its course, especially 
if it pass material objects, which can be marked, together 
with the place of observation. The aspect of the body and 
its train. The duration of the course. kind and in- 
tensity.of a eePaNs and the interval of time between the re- 
. alosion.. Other observations may be both useful 
and interesting, though the . 
piineipal, eee SEs. AE present, to 
But if ever the phenomena shall beco 
2 me settled and 
known, and every fact disclosed which rational curiosity can 
Search out respecting these bodi i 
Hon of principal interest to be answ 
purpose do they promote? Their ‘iiigheee and the general 
