ASTRONOMY. 
Of this, and other stars, which have appear- 
ed since that time, we have the following 
history by Dr. Halley. “ The first new 
star in the Chair of Cassiopeia was not seen 
by Cornelius Gemma on the 8th ofNovem- 
bc,r, 1572, who says, he, that night, consi- 
dered that part of the heaven in a very se- 
rene sky, and saw it not ; but that the 
next night, November 9, it appeared, with 
a splendor surpassing all the fixed stars, and 
scarce less bright than Venus. This was 
not seen by Tycho Brahe before the 11th of 
the same month ; but from thence he as- 
sures us that it gradually decreased and 
died away ; so as in March,' 1574, after 16 
months, to be no longer visible ; and at this 
day no signs of it remain. Its place 
in the sphere of fixed stars, by the accu- 
rate observations of the same Tycho, 
was 0 s 9° 17' a l ma * <y>, with 53° 45' north 
latitude. Such another star was seen 
and observed by the scholars of Kepler, to 
begin to appear on September 30, St. Vet. 
anno 1604, which was not to be seen the 
day before ; but it broke out at once with 
a lustre surpassing that of Jupiter; and, 
like the former, it died away gradually, and 
in much about the same time disappeared 
totally, there remaining no footsteps thereof 
in January, 1605-6. This was near the eclip- 
tic, following the right leg of Serpentarius ; 
and by the observations of Kepler and 
others, was in 7' 28° 00' a l ma * °p, with 
north latitude 1° 56'. These two seem to be 
of a distinct species from the rest, and nothing 
like them has appeared since. But between 
them, viz. in the year 1596, we have the 
first account of the wonderful star in Collo 
Ceti, seen by David Fabricius on die 14th 
of August, as bright as a star of the third 
magnitude, which has been since found to 
appear and disappear periodically ; its pe- 
riod being precisely enough seven revolu- 
tions in six years, though it returns not al- 
ways with the same lustre. Nor is it ever 
totally extinguished, but may at all times 
be seen with a six feet tube. This was sin- 
gular in its kind, till that in Collo Cygni 
was discovered. It precedes the first star 
of Aries 1° 40', with 15° o7‘ south latitude. 
Another new star was first discovered by 
William Jansonius in the year 1600, in 
Pectore, or rather in Eductione Colli Cygni, 
which exceeded not the third magnitude. 
This having continued some years, became 
at length so small, as to be thought by 
some to have disappeared entirely ; but in 
tfie years 1657, 16511, and 1659, it again 
arose to the tliird magnitude ; though soon 
after it decayed by degrees to the fifth or 
sixth magnitude, and at this day is to be 
seen as such in 9 s 18° 38' a l ml> * <y 
with 55° 29' north latitude. A fifth new 
star was first seen by Hevelius in the year 
1670, on July 15, St. Vet. as a star of the 
third magnitude; but by the beginning of 
October was scarce to be perceived by the 
naked eye. In April following it was again 
as bright as before, or rather greater than 
of the third magnitude, yet wholly disap- 
peared about the middle of August. The 
next year, in March, 1672, it was seen 
again, but not exceeding the sixth magni- 
tude : since when, it has been no further 
visible, though wehave frequently sought for 
its return; its place is 9‘ 3° 17' a l ma <ys, 
and has lat. north 47° 28'. The sixth and 
last is that discovered by Mr. G. Kirch in 
the year 1686, and its period determined to 
be of 404| days ; and though it rarely ex- 
ceeds the fifth magnitude, yet it is very re- 
gular in its returns, as we found in the year 
1714. Since then we have watched, as the 
absence of the moon and clearness of the 
weather would permit, to watch the first 
beginning of its appearance in a six feet 
tube, that, bearing a very great aperture, 
discovers most minute stars. And on June 
15 last, it was first perceived like one of the 
very least telescopical stais ; but in the rest 
of that month and July, it gradually in- 
creased, so as to become in August visible 
to the naked eye : and so continued till the 
month of September. After that, it again 
died away by degrees : and on the 8th of 
December, at night, was scarcely discern- 
ible by the tube ; and as near as could be 
guessed, equal to what it was at its first ap- 
pearance on June 25, so that this year it has 
been seen in all near six months, which is 
but little less than half its period ; and the 
middle, and consequently the greatest bright- 
ness, falls about the 10th of September.” 
The late improvements in astronomy, 
and particularly those in the construction 
of telescopes, have now given astronomers an 
opportunity of observing the changes which 
take place among the stars with much 
greater accuracy than could be formerly 
done. In a paper in the 76th volume of the 
Philosophical Transactions, Mr. Edward 
Pigot gives a dissertation on the stars sus- 
pected by the astronomers of the last century 
to be changeable. For the greater accuracy 
in tiie investigation of his subject, he divides 
them into two classes ; one containing 
those which are undoubtedly changeable, 
and the other those whieh are only suspected 
