KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 43. N:o 10. 15 
where m is the highest magnitude considered, N, and h being functions of the lati- 
tude — approximately: 
Ii = 26 
Other papers on the distribution of stars are: 
A. M. Clerke. The distribution of stars, Astronomy and Astrophysies 12: 1893 pag. 5315; 
T. W. Backhouse, The Sidereal Universe, referred to in the Monthly Notices of the Royal Astronomical 
Society Vol. L pag. 374; 
R. A. Proctor, Statement of views respecting the Sidereal Universe, Monthly Notices Vol. XXXIII, 
pag. 539; 
J. Herschel, On the law of distribution of nebulx and clusters of stars over the surface of the heavens. 
Results of astronomical observations, made at the Cape of Good Hope, pag. 133. 
7. Distribution of Spiral Nebulce. 
The attention to a certain law of distribution of the nebulx was raised by J. 
HERSCHEL with a statistic inquiry, by which he succeeded in pointing out two vast 
dominions of nebul&x, each surrounding the poles of the Galaxy. This numerical sta- 
tement, which, according to HERSCHEL, must be considered as the expression of a 
real law of nature, was furthermore left unexplained. 
The next one to take up the question of the distribution of nebulae was CLEVE- 
LAND ÅBBE.! His researches refer to the distribution of different classes of celestial 
objects, viz, — 1) Clusters, 2) Globular Clusters, principally condensed in the Milky 
Way, 3) >»resolvable nebule», of which merely 12 of 397 are in the Milky Way, 
4) unresolvabie nebule of which only 64 of 4053 are situated in the Milky Way. 
The conclusions are confined in the following suggestions: 
1. The Clusters are members of the Via Lactea and are nearer to us than the 
average of its faint stars. 
2. The Nebul&e resolved and unresolved lie, in general, outside the Via Lactea, 
which therefore is essentially stellar. 
3. The Visible Universe is composed of systems, of which the Via Lactea, the 
two Nubecule and the Nebule are the individuals. 
The author conceives the paucity of nebulxe in the immediate neighbourhood 
of the Via Lactea to be partially due to the comparative glare of the intervening 
multitude of stars; but their persistent paucity, when the limits of that band are 
supposed greatly increased (to ”/se of the entire celestial surface) implies, according 
to him, that the Nebulze are actually either fainter or scarcer in the neighbourhood 
of that plane, or that the visible universe is less extended in that direction. CLEVE- 
LAND ÅBBE gives also a statistic of planetary nebule, which he finds follow almost the 
law of distribution for the Clusters. In accordance with his previous views, the 
planetary nebulge may be classed with the clusters as regards their arrangement and 
distance from us, and are to be considered as gaseous globes belonging to the Via 
Lactea. Yet this later conviction may be subjected to some doubt, as a more par- 
ticular discussion of the distribution of the Planetary Nebulce comes up to prove. 
! On the distribution of the nebule in space. Monthly Notices of the Royal Astronomical Society, Vol. 
XXVII, 1867 pag. 257. 
