96 On Shooting Stars. 
abundance of speculation and crude conjecture. These speculations 
are by no means confined to the brains of the illiterate, but are re- 
corded every where in Encyclopedias and Scientific Journals. Not 
content with stating what is known respecting shooting stars, or rath- 
er unwilling to acknowledge what is not known, almost every writer 
seems to have considered it incumbent npon him to amuse his readers 
with the creations of his own fancy. One sagely informs us that 
phosphuretted hydrogen rising from the surface of the earth in unbro- 
ken columns to very considerable heights, spontaneously takes fire 
at the top and burns rapidly downward, presenting the appearance of 
a falling star. Another speaks of them as Jack-a-lanterns rising high 
in the air, dependent upon the wind for the direction of their motions. 
This idea that shooting stars follow the course of the wind is very 
common, and appears at first view to furnish a plausible explanation 
of their motions. For we may easily suppose particles of phosphu- 
retted hydrogen to be floating in the air; the difficulty is to supply 
the power which puts them in motion. But when we learn that 
these meteors are frequently more than a hundred feet in diameter, 
and that they move with a velocity greater than that of the earth in 
its orbit, the inadequacy of all such hypotheses to explain the phe- 
nomenon in question, must be at once conceded. Facts like these 
respecting their velocities and magnitudes, can be ascertained only 
from simultaneous observations by two or more persons at different 
stations ; and hence it must be apparent that such observations fur- 
nish the only basis for definite knowledge on the subject. If at two 
stations, whose distance from each other is known, the apparent place 
of a meteor in the heavens is noted, it is clear that we have the 
means of determining its height from the surface of the earth; and 
if like observations are made both upon the beginning and end of the 
meteor’s course, the length of its path is known, and hence having 
the time of its flight, we have also its velocity.-—So obvious a meth- 
od of arriving at some definite knowledge on the subject, it might be 
supposed would have been often resorted to. The fact however 
has been otherwise. Among the most extensive observations of 
this kind are those made by Professor Brandes of Leipsic ; and as 
they are but little known in this country, it may be acceptable to 
some readers of the Journal, to be furnished with an abstract of them. 
They compose one of a series of tracts, entitled Unterhaltungen fuer 
Freunde der Physik und Astronomie. The following 
their author, are from the Conversations-Lexicon der 
neuesten Zeit und Literatur. 
