9 
Satellite are one million, seventy-four thousand, one hundred 
miles, and eight hundred and forty thousand, six hundred miles ; 
the speed of the former in its orbit 1s twenty-seven miles per 
second,- and of the latter, fifty-six miles per second. Roughly 
speaking, Algol is less than half the mass of the sun. The 
observations of Mr. Monck, of Greenwich, zonfirm those of Pro- 
fessor Vogel. 
Mr. Isaac Roberts, the celebrated amateur photographer, has, 
by means of his stellar photographs, done good work in deter- 
mining the variability of Algol, and similar stars. By his method 
all atmospheric, actinic, and chemical changes are eliminated ; 
_thus the study of the variability of the stars can be pursued under 
the most favourable conditions. 
A novel apparatus has been fixed to the Great Lick Telescope, 
by means of which it is hoped that still better photographs may be 
taken of the moon, which will yet farther increase our acquaintance 
with our satellite. Professor Holden has already taken five 
photographs of the successive phases of the moon which give an 
admirable representation of the long lunar day, from sunrise to 
sunset. These photographs are published in America at popular 
prices. Some superb photographs of the moon, which show the 
lunar craters in the most striking manner, have also been taken in 
Paris, by M. M. Paul and Prosper Henry. 
Theophilus, the deepest of the lunar craters, and whose diameter 
is sixty-four miles, is seen standing up eighteen thousand feet 
above the chasm. The diameter of these photographs is over 
one yard, and they are said to surpass even those from the Lick 
Observatory in clearness of definition. 
From Grahamstown last autumn was reported the discovery of 
a new comet, or at any rate of one whose orbit brought it for the 
first time within our view. It appeared at 7.45 p.m. on October 
27th, on the western horizon, and after performing a rapid 
journey of at least ninety degrees it disappeared in the south east 
at 8.32 p.m., having only been visible for about three quarters of 
an hour. When first seen it was about thirty degrees in length, 
but it soon attained the length of ninety degrees, and stretched 
along the southern horizon like a ‘ribbon of weird grey light.” 
This comet possessed no visible nucleus, and was of extreme 
tenuity, for the lustre of several bright stars, across which it 
passed, was not diminished by its transit. The moon at the 
time was at the full. 
A remarkable meteor is said to have passed over Iowa last May, 
having a comet-like tail. Its passage was accompanied by a 
rumbling hissing noise, and it burst some eleven miles from 
Forest City. The fragments which were scattered over the 
