724 
furnishes an indication: the fantastically twisted and ramified shapes 
of the dark regions in their various gradations of blackness, which 
present themselves on the chart of Dyson and Merorre, and are 
even more marked on the photographs by BaRNARD !), are a strong 
indication to the existence of absorbing nebulae in these Taurus 
regions. This indication is corroborated, if we calculate the influence 
of actual star-voids in space on the number of stars of different 
magnitudes. 
We assume that in the line of sight the space from 7, to 7, = 1,585r, 
is completely empty (over a region from @, to 9, +1 therefore). 
In the integral, representing the number of stars A, of the magnitude 
m, the part between the limits o, and ge, + 1 is lacking, thus 
ro+0,22 
1 - 
Am == Aj, (: = == 10-2? dz ) 
V 2 log € 
To 
in which rz has the same signification as in the previous communi- 
cation. If we calculate these values for a certain value of o, (eg. 
0, = 6,95, whereby the falling-off of stars-becomes a maximum 
for m= 9), and from that the total numbers WV’,,41, and the loga- 
rithmic defect log N'/y, we find: 
m. | log N’/N m. | log N’'/n 
3 10 
—0,028 — 0,080 
Ad yj 11 
| — 040 — 069 
Bie 12 
— 055 — 056 
6 13 
— 069 — 043 
7 14 
— 080 — 031 
8 cel 15 
IEN | 16 
| — 086 — 014 
10 -| 17 
With a void, extending over a unity in 9, there is therefore a 
lack of 18°/, at the utmost in the total number of stars. To produce 
such a strong defect as observed in the Taurus regions, the void 
must extend over many unities in g. If such holes do not extend 
1) KE, E. BARNARD. On a nebulous groundwork in the constellation Taurus. 
Astrophysical Journal 25, 3. 
