( 732 ) 
— = a and from the point {o,o\. This vector describes along c p a 
positive angle 2 ,t, just as the existing one along x p . If then according 
to Schoenplies we fill the annular domain between x p and c p with 
simple closed curves enveloping each other and as functions of a 
cyclic parameter passing continuously into each other, then we can 
thereby at the same time make the vector distribution along x p pass 
Continuously into that along c p , and in this way give to the annular 
domain between x p and c p a finite continuous vector distribution, 
vanishing nowhere. Inside x p we have now obtained a finite con¬ 
tinuous vector distribution, having but one point zero, namely the 
point ( o y o)p , and that a source point of very simple structure, which 
we shall call a radiating point . 
And the inner domain of x is covered with a finite continuous 
vector distribution passing on x into the original one and possessing 
inside x, instead of the original point zero P, n radiating points. 
Let us furthermore suppose that for a positive circuit of * the 
vector describes a negative angle 2rcrr. In an analogous way as 
above we then divide the inner domain of x into n regions G p with 
boundaries x pt and we bring along each of these boundaries such a 
vector distribution, that for a positive circuit of x p the vector describes 
a negative angle 2 jt. 
The curves c p are introduced again as above, but inside and on 
c p we introduce a finite continuous vector distribution vanishing only 
in the point (0,0)^, which is directed along the lines x p y p = a. For 
a positive circuit this vector describes along c p a negative angle 2 jt, 
just as the existing vector along x p . 
So the annular domain between x p and c p can be filled up in an 
analogous way as just now with a finite continuous vector distribu¬ 
tion vanishing nowhere, and the whole distribution inside x p possesses 
then only one point zero, namely the point (0,0',,, having four 
hyperbolic sectors of very simple form (the four separating parabolic 
sectors are each reduced to a single line}, which structure we eha- 
racterize by the name of reflexion point. 
After this the inner domain of x is covered with a finite continuous 
vector distribution passing on x into the original one and possessing 
mside x, instead of the original point zero P, n reflexion points. 
Let us finally suppose that for a circuit of x the total ,angle 
described by the vector is zero. We can then choose inside * such 
a simple closed curve c, that in a suitable system of coordinates its 
equation can be written in the form x'+y' = r*. Inside and on c 
we introduce a finite continuous vector distribution vanishing nowhere. 
