describes it as an object shaped like a dumb-bell, double-headed 
shot, or hour-glass; the elliptic outline being filled up by a more 
feeble and nebulous light, as shown in fig. 12, copied from the 
drawing of Sir John Herschel. 
Such was the form and character assigned to this object until 
Lord Rosse had constructed larger and more powerful instruments, 
and when he directed upon it a twenty-seven foot reflector with 
three feet aperture, it assumed the appearance shown in fig. 13, 
where a faint indication of stars can be seen; subsequently, 
57 
TELESCOPIC TESTS—NEBULA. 
in fig. 10, a faint and rather indistinct indication of minute stars 
being perceptible; but when a still higher power is brought to 
bear upon it, the object will be 
seen as what it really is/ a 
dense mass consisting of couiftless 
numbers of separate stars, as 
shown in fig. 11. 
18. Different nebulae require 
telescopes of different powers, and 
many have never been yet re¬ 
solved, even by the greatest 
powers that scientific art has yet 
produced. In proportion, how¬ 
ever, as the telescopic power has 
been increased, more and more 
of these objects have been re¬ 
solved. A remarkable illustration 
of this state of progressive discovery is supplie 
well-known nebula, first observed and drawn 
Herschel, as seen in a twenty-foot reflector. Sir John 
Fig. 10. 
