708 
That objects of this kind do not present themselves in the Galaxy 
alone, became evident from the investigations of BARNARD, who 
published a list of 182 mostly small, dark objects, *) which, though 
they were best discernible against the bright background of the 
Galaxy, are yet to be found also outside it, and which here and 
there are even directly visible by means of telescopes as intensely 
black spots. The wide extension of this absorbing substance became 
evident in yet another way, by an investigation of the generai 
distribution of the stars up to the 11' magnitude’). It was found 
here that around two places with a considerable deficiency of stars, 
in Taurus and Ophiuchus, as around two centres of obscuration, there 
are wide regions where the number of stars is below the normal. 
As this investigation was carried out by means of averages over 
extensive regions, it could only give a general image, which could 
be equally well explained by a certain distribution of the stars in 
space, as by the effect of an absorption. But it became evident that 
in the one kernel, in Taurus, the distribution of the density of the stars 
to the 14% magnitude was very irregular, and that the poorest 
regions were precisely those, where, according to BARNARD’s catalogue, 
a number of black objects have accumulated; this points to absorpt- 
ion as the most likely explanation of the general distribution of 
stars over the sky we had found. 
We get a still clearer image of the irregularities in the star- 
distribution in this Taurus-region by an investigation of Dyson and 
Metottre*) by means of the FRANKLIN-ADAMS plates, which show the 
stars up to magnitude 15,8. The counts proved that there are mainly 
three regions of strongest obscuration, the irregular shapes of which 
are visible on the adjoining chart: about 3520™ + 30° (S.W. of 
5 Persei), 4'30™ + 26° (between the Pleiades and Tauri) and 
5h20m + 25° (S.W. of 3 Tauri). By comparing «the numbers of stars 
of different sources, they come to the same conclusion, that these 
absorbing nebulous masses must be situated relatively near to us. 
“Thus, taking the area as a whole, we find the number of stars is 
about one fifth of the normal number whether we go down to 
magnitude 97,0, 11,0 or 14,0. This would seem to indicate, that 
1) E. E. BARNARD, On the dark markings of the sky. Astrophysical Journal 49, 
1. (Jan. 1919). 
2) A. PANNEKOEK, On the distribution of the stars of the 11th magnitude. 
Monthly Notices of R. A. S. 79, 333 (March 1919). 
8) Str F. W. Dyson and P. J. Merorre, The region of the sky between R.A, 
3h and 5h 30 m and N. Dec. 20° to 35°. Monthly Notices of R. A. S. 80. 3 
(Nov. 1919). 
