The altitudes given in the table are represented to the eye in 
corresponding shooting star at its appearance and disappear 
ance, The length of the line represents therefore the amount of 
descent, not the length of the path. he dotted lines stand for 
. those meteors of which the heights of only the middle points 
are computed. At the end of this division of the diagram is a 
heavy line that represents the mean of all the paths as computed 
above 
In the second division of the diagram is given in like manner 
a representation of the paths of 39 meteors observed at New 
The large majority of the paths from which these results are 
obtained belong to August meteors, 
It appears, then, that the region in which the November re 
teors appear and disappear, is 15 or 20 miles higher than t 
corresponding region for the August meteors. If the decrease 
of density of the atmosphere at this elevation follows the same 
law as near the earth’s surface, the air in the latter region 18 
forty or fifty times as dense as in the former. : 
__ The most plausible explanation of this remarkable fact is, that 
__ the two groups of bodies differ in their chemical and mechanical 
_ constitution; the November group being more inflammable than 
that of August, as 
+. Itis altogether unlikely that any of the meteors became Vist 
__ ble at a greater altitude than 125 or 150 miles, The faeility for 
error in observing is very considerable. It seems impossible 
however to explain in this way the large difference between the 
_ Means of the computed altitudes of the two groups. 
