( 752 ) 



I sliall now eiideavoni' fii-sl to investigate in tlic following when 

 it is possible to hi-ing through two eiinal circles placed in [)arailel 

 planes a cyclic minimal surface and then to calculate the part of the 

 minimal surface extended between those circles. 



When for both circles the radius 11 is taken e(pial to J, the centres 

 J/(^, '^"^1 M' { — '§., — ?) are situated in the A'/f-plane symmetrically 

 with respect to the origin and their planes are parallel to the XV- 

 plane, the question is whether the two e(piations : 



^ r dw 



§ z=z k en u 1 , ij =: kit 



=: m Gil n 



admit of suitable solutions for /• and u. If these are found, we have 

 h =^ en a and both parameters I) and k of the minimal surface are 

 known. 



In order to investigate the indicated erpiations we regard for the 

 present in the sS-plane 'è and ^ as variables and we consider the 

 curve which is described by point (b, ?), when for constant k {\ie 

 variable u describes the range of values tVoni to A". We have : 



ê(0) = , ?(0)=:0, 



So for all values of k the curve will run from the origin to 

 point ^4 on the s-axis (see the diagram). 



