224 Dr. Herschei/s Observations on 
patterns to adjust our definition by. I should, for instance, say 
of planets, 
1. They are celestial bodies, of a certain very considerable 
size. 
2. They move in not very excentric ellipses round the sun. 
g. The planes of their orbits do not deviate many degrees 
from the plane of the earth's orbit. 
4. Their motion is direct. 
5. They may have satellites, or rings. 
6. They have an atmosphere of considerable extent, which 
however bears hardly any sensible proportion to their diameters. 
7. Their orbits are at certain considerable distances from 
each other. 
Now, if we may judge of these new stars by our first criterion, 
which is their size, we certainly cannot class them in the list 
of planets : for, to conclude from the measures I have taken, 
Mercury, which is the smallest, if divided, would make up more 
than 135 thousand such bodies as that of Pallas, in bulk. 
In the second article, their motion, they agree perhaps suffi- 
ciently well. 
The third, which relates to the situation of their orbits, seems 
again to point out a considerable difference. The geocentric lati- 
tude of Pallas, at present, is not less than between 17 and 18 de- 
grees ; and that of Ceres between 15 and 16 ; whereas, that of the 
planets does not amount to one half of that quantity. If bodies 
of this kind were to be admitted into the order of planets, we 
should be obliged to give up the zodiac ; for, by extending it to 
them, should a few more of these stars be discovered, still 
farther and farther deviating from the path of the earth, which 
