108 
POPULAR SCIENCE REVIEW. 
With a telescope of three-fourths the original size nothing was visible. The 
second variable nebula is situate at 3h. 38m. of R.A. , and -f- 23° 23' of Decl. 
In 1859, October 19, Tempel describes it as large and bright, with a two- 
foot telescope. In December, 1860, it was scarcely visible in a six-foot 
telescope ; whilst, at the present time, it is scarcely visible in the largest 
instruments. It is to Professor D’ Arrest that we are indebted for these 
startling discoveries, which completely alter all our notions in respect to 
nebulse. It is very remarkable that the two new variable nebula are 
situate within nine and eight degrees from the missing nebula; of last 
February. The idea of a cosmical cloud, which has been imagined in 
order to explain other phenomena, will doubtless be reverted to in the 
present instance. There are very few nebulae in this region of the heavens, 
although many clusters and knots of stars. Among others, we have a 
double nebula, R.A. 3h. 11m., 40° 43' ; a nebula, R.A. 3h. 20m., 
Dec. -f- 36° 45' ; a nebulous star, R.A. 3h. 59m., Dec. + 30° 20' ; and a 
single nebula at R.A. 4h. 19m., Dec. -j- 34° 54'. 
It will be some years be- 
fore Mars is seen to such 
perfection as at the present 
time. As it will be the only 
telescopic object among the 
planets for the next few 
months, it will of course be 
duly looked after. It will 
be the most brilliant object 
in the heavens during the 
months of October, Novem- 
ber, and December, and will 
be visible even for the first 
three or four months of the 
year 1863. We give a draw- 
ing of its appearance on 
September 17. 
A striking instance of the 
unnoticed changes which are 
constantly going on in the 
heavens is the case of the star in Ophiuchus, marked (5) in catalogues 
and maps. Although the variations in brilliancy of this object have 
been very decided, yet it has not been until the last few months that 
they have been remarked, and duly inquired into. It has been found that 
this star fluctuates through all grades of brightness between the 6th and 
31 magnitude. It was reckoned of the former lustre in July, 1849, by 
Argelander, whilst in June, 1862, it had increased to the latter. The 
name of Argelander is a sufficient guarantee for the correctness of the first 
observation, whilst that of the latter can be verified at the present time. 
Doubtless, the future changes in the brilliancy of this object will be a 
matter of considerable moment. One has only to compare the faintest of 
the seven stars in the “ Plough” with that which is merely visible to the 
naked eye, to realize the difference between the two objects. 
Mars, September 17 , ISG2, at 11 p.m. 
by J. Buckingham, Esq., F.R.A.S. 
