1
One of the few nebulæ known to vary in brightness and form.
2
On many of the diagrams the position of nebulæ is indicated.
3
It is a constellation rich in double and multiple stars, clusters, and nebulæ.
4
Many of the nebulæ serve as tests both for illumination and defining power.
5
Ether, atoms, and nebulæ are the raw material of their trade.
6
We could not refuse to admit as possible such an origin for nebulæ.
7
Indeed, it is a question whether all nebulæ are not to some extent spiral.
8
She and --are twin nebulæ who think themselves constellations.
9
They are full of nebulæ and star-clusters, and show striking evidences of spiral movement.
10
Since then it has been shown to be a prominent constituent of nebulæ and hot stars.
11
Laplace's famous theory was that the planets and the earth were formed from great whirling nebulæ.
12
We now come to a still more extraordinary phenomenon of this kind -the Pleiades nebulæ.
13
Yet no speculation upon the origin of species or the function of the nebulæ filled his mind.
14
Hundreds of thousands of nebulæ, besides even vaster irregular stretches of nebulous matter, exist in the heavens.
15
No stars, no nebulæ, no meteoric matter, nor even the smallest particle of cosmic dust-absolutelyempty space.
16
The wonderful aspect of the admixtures of nebulæ and star-clusters in Sagittarius has been described in Chapter 1.