for ascertaining the distances of clusters of stars, &c. 453 
In my last paper I have drawn the attention of astronomers 
to the condition of the milky way, as being the most brilliant, 
and beyond all comparison the most extensive sidereal 
system ; and have also shown that the globular space con- 
taining all our visible stars, is situated within its compass ; I 
shall therefore now make the plane of it the principal dimen- 
sion of my figure ; then if the line a b represent this plane, a 
perpendicular drawn from the centre c of the figure to d and 
to e, will be directed towards the north and south poles of it, 
and the situation of the globular space in the figure will be 
like that of a celestial globe adjusted to the latitude of 30 
degrees, having the milky way in the horizon, the 190th 
degree of right ascension in the meridian, and the 60th 
degree of north polar distance in the zenith. 
From this description of the arrangement of the stars 
within the globular space, and its situation in the plane of the 
milky way, it is evident that, having already an expression 
for the position of a celestial object in two dimensions, the 
addition of the third, which is its profundity or central dis- 
tance, may be represented by a line of a length that is 
proportional to the diameter of the globular space ; and if 
this line be a continuation of the direction in which the object 
is seen from the centre, its termination will show the real 
place of the object, and point out its situation with respect to 
the great sidereal stratum of the milky way. 
An observer who looks at a celestial globe, and wishes to 
see the angle of the direction of the line in which an object is 
seen from the centre, will for this purpose turn the globe 
horizontally till the plane of the azimuth circle is at right 
angles to the line in which he looks at it ; or, if more con- 
