480 Dr. Herschei/s Catalogue 
truly be said to be in the plane of the milky- way, yet I am now 
convinced, by a long inspection and continued examination of 
it, that the milky-way itself consists of stars very differently 
scattered from those which are immediately about us. But of 
this, more will be said on another occasion. 
From the detached situation of insulated stars, it appears that 
they are capable of being the centres of extensive planetary 
systems. Of this we have a convincing proof in our sun, which, 
according to our classification, is one of these stars. Now, as 
we enjoy the advantage of being able to view the solar system 
in all its parts, by means of our telescopes, and are therefore 
sufficiently acquainted with it, there will be no occasion to enter 
into a detail of its construction. 
The question will now arise, whether every insulated star be 
a sun like ours, attended with planets, satellites, and numerous 
comets ? And here, as nothing appears against the supposition, 
we may from analogy admit the probability of it. But, were we 
to extend this argument to other sidereal constructions, or, still 
farther, to every star of the heavens, as has been done fre- 
quently, I should not only hesitate, but even think that, from 
what will be said of stars which enter into complicated sidereal 
systems, the contrary is far more likely to be the case ; and that, 
probably, we can only look for solar systems among insulated 
stars. 
II. Of Binary sidereal Systems, or double Stars. 
The next part in the construction of the heavens, that offers 
itself to our consideration, is the union of two stars, that are 
formed together into one system, by the laws of attraction. 
If a certain star should be situated at any, perhaps immense. 
