PROGRESS OF METEORIC ASTRONOMY IN AMERICA. 311 
If the testimony of Huggins and of Liveing and Dewar 
represents the observed phenomena, and their observations 
have not yet been disproved, then most of the broad theories 
of Lockyer, which assume a common origin and structure 
for aurorae, nebulae, comets, and stars, lacks a basis of ob¬ 
served facts, resting wholly, so far as the aurora and nebulae 
are concerned, on approximate coincidences in the spectra, 
while the assumed telescopic appearance of comets at aphe¬ 
lion is a creation of the imagination. 
Conclusions. 
Attention has been called to these various theories relat¬ 
ing to comets and meteors simply with a view to emphasiz¬ 
ing the fact that none of the systems, whether simple or 
complex, seems to explain all the observed phenomena. 
As a scientific explanation, the direct and simple is always 
preferable to the indirect and involved method, and this 
safe precept should be the guide in all investigations of the 
apparent physical connection between comets and meteors. 
It seems to me that the true theory of the origin and the 
relations of comets and meteors is yet to be discovered. 
When asked to give my own theory of these bodies I can 
only reply that I have none. At the same time I see less 
objection to the following hypotheses than to any of those 
now doing duty as theories: 
Meteors and meteorites are solid iron or stony bodies and, 
whatever their origin, are now members of the solar system. 
Comets are composed chiefly of gaseous matter, and originate 
outside of the solar system. Some of these bodies on enter¬ 
ing the sphere of solar attraction are so far drawn away 
from their original orbits by the masses of the sun’s outer 
satellites that they become permanent members of the solar 
system. Of these, at least four have become entangled in 
the immense aggregations known as meteor streams and 
have adopted the orbits of their captors. The meteors still 
remain meteors, however, and the comets retain their former 
identity and peculiar structure. 
