E 
Pe me 
a ee ge 
ied 
J. H. Lane on a Mode of Photographing Meteors. 45 
path of the body must be driven before it, and receive a ve- 
locity equal to that of the body, or at least to a large fractional 
part of it. The mass of air which the body must have encoun- 
tered in losing the thousandth part of its velocity, will, there- 
fore, be of the order of a thousandth part of that of the body. 
ith the loss of a thousandth part of the velocity, the loss of 
the body’s own vis viva will correspond to the quantity of heat 
that would raise the temperature of its weight of water 448° Fah. 
If after making allowance for the motion communicated to the 
displaced air—approximately one half—and for the quantity of 
generated heat which this air retains and carries off, we assume 
that a twentieth part of the above 448° enters into the body it- 
self, and by reason of the rapidity of its production is collected 
‘in asuperficial coating of a hundreth part of its mass, and give 
this a specific heat within that of water, we shou find an eleva- 
tion of temperature of 2240° or upwards. The inference we 
would draw from these considerations seems confirmed by what 
we know of the great length of the visible flight of meteors, and 
of the great elevation of the region of atmosphere in which it 
be as the foregoing considerations lead us to peed BE the dis- 
] 
large number of meteors, will be likely to afford us complete 
assurance on the subject, by pointing out certain laws of the re- 
sistances at different altitudes. A moderate degree of accuracy 
in the absolute determination of the orbits, except, when they 
make a near approach to the parabola, will be sufficient to an- 
swer all the questions of interest that will be 
which a knowledge of the orbits would have any bearing. 
Whether the November meteors, for instance, move through 
regions that would identify them with the Zodiacal light, accord- 
ing to the theory of the late Prof, Olmsted, is a question that 
would receive an absolute determination. 
