Title:
On the general “nodal”  Enriques surface/ Over het  algemene “nodale” Enriques oppervlak.

Abstract:
This is joint work with Hans Sterk. 
Some time ago  in our seminar I gave the classical geometric construction of the general
Enriques surface by giving a specific 10-dimensional family of such surfaces. What about
special Enriques surfaces? These must be “nodal” (to be explained in the lecture). We
give a very concrete geometric construction of a 9-dimensional family of such surfaces.
This captures the general “nodal” Enriques surface. The automorphism group of its generic 
member is determined; it is an infinite discrete group.