Stonsy— The known part of Natures Work. ee oN 
The farthest stars visible to us are probably less than’10,000 
times farther than the few whose parallax can be directly measured, 
since a star sending us one hundred-millionth part of the light of 
Sirius would probably not be visible. 
If this view is correct, Av, which is the middle sub-section of 
Group A, provides places to represent the distances of the stars 
visible to the naked eye, along with a// those which our telescopes 
ean reach. Accordingly, a sphere of which the radius is a metro- 
twenty, or some two or three metro-twenties, would include our 
whole stellar universe. Now, our table extends 1000 times beyond 
the column of metro-twenties; so that the greater part of sub- 
section Aw makes provision for measuring distances as much 
farther out than the most distant star known to us, as a sphere 
with a mile for its radius ranges beyond a concentric sphere with 
less than a yard for its radius. 
It is just possible that the inner portion of this extension is 
necessary to represent man’s present knowledge, that, in fact, some 
of the non-gaseous nebule, e.g. the great Nebula in Andromeda, 
may be stellar “‘ universes” distinct from ours, and located some- 
where within the larger sphere. Ii so, when we looked upon the 
speck of light which brightened up in the Nebula of Andromeda a 
few years ago, we may have been then actual spectators of an event 
which really happened some hundreds of thousands of years ago, 
the waves of wireless telegraphy which communicated the informa- 
tion to us having occupied the whole of that immense time upon 
their swift journey. 
OF THE RELATION BETWEEN LIGHT AND OUR SCALE. 
This leads us to consider the relation in which light stands to 
our survey. It is useful to do 
80, since it gives unity to our 
survey to consider how our table O 000 000 000 O 000 000 
StrnpAr Distranogs. | PLANETARY. 
is related to light, which in one 9 467 Bes @ 7 
. . ° SS —S_ = 
direction reaches, by the minute- Cis the distance : re is the distance 
G which light will vel which light will trave 
ness of its waves, the borderland in one hundred mil GTO Tee 
‘ 3 ions of years, 
of molecular magnitudes, and in Fie. 5. 
the other direction, by reason of its great speed, can traverse im- 
mense distances in periods of time which we can grasp. The rela- 
tionship is exhibited in the lower section of fig. 6, which gives the 
