  Values for the vacuum energy of scalar fields under Dirichlet and Neuman
boundary conditions on an infinite clylindrical surface are found, and they
happen to be of opposite signs. In contrast with classical works, a complete
zeta function regularization scheme is here applied. These fields are regarded
as interesting both by themselves and as the key to describing the
electromagnetic (e.m.) case. With their help, the figure for the e.m. Casimir
effect in the presence of this surface, found by De Raad and Milton, is now
confirmed.
