24 Dr. Herschei/s Miscellaneous Observations. 
about a condensed small part of five or six seconds in diameter ; 
which resembled a kind of nucleus, but had not the least ap- 
pearance of a solid body. Beside the scattered, and gradually 
diminishing light, which reached nearly to a distance of three 
minutes every way beyond the bright centre, there was also 
a faintly extended, ill defined, pretty broad ray, of about 15 
minutes in length, directed towards the north following part of 
the heaven, which might be called the tail of the comet. 
Its place for the same night (Dec. 16th) was determined by 
a five-feet Newtonian Sweeper , carrying an equilateral tri- 
angle in the focus of the eye-glass, not so large but that the 
three intersections, made by the wires at the three angles, may 
be distinctly perceived. At 5 h 49' 40 ", 6 it preceded the 6th 
Lacerta 4' 58", 5 in time, and was 52' 14", 5 more north than 
that star. 
On the periodical Appearance of 0 Ceti. 
The changeable star in the neck of the Whale, 0 Ceti, con- 
tinues its variations as usual, but with some considerable irre- 
gularities of brightness. 
In the year 1779, as we have seen*, it excelled a Arietis so 
far as almost to rival Aldebaran ; and continued in that state a 
full month. 
In 1780, its greatest brightness was only like that of $ Ceti. 
In the year 1781, it did not come up to the brightness of 
In 1782, this star increased to the size of /3 Ceti, and conti- 
nued bright for more than twenty days. 
In 1783, it did not only vanish to the naked eye, as usual, but 
disappeared so completely, that I could not find it with a 
* Phil. Trans. Vol. LXX. page 338. 
