A principal table containing five resolution-dependent blend wavelengths
together with their corresponding pixel displacement 
and
discretisation stability parameter s for two very different
Ar-to-Th line strength ratios, as well as five restricted tables
containing only the blend wavelengths of a selection of strong stable
calibration lines for each of the spectral resolutions discussed in this paper
are published by A&A at the Centre de Données de Strasbourg, where they are
available in electronic form: see the Editorial in A&A 1993, Vol. 280,
page E1. These tables are also available on the webserver of the Astrophysics
Data Reduction Centre of the KSB/ORB: http://midas.oma.be or through
anonymous ftp from
midas.oma.be.
Acknowledgements
Both authors carried out the research in the framework of projects
initiated and financed by the
Belgian Federal Scientific Services
(DWTC/SSTC), contract Service Centres and Research Networks No. SC/005
and contract I.U.A.P. No. P4/05. They are grateful to
M. David and
W. Verschueren for discussions and a critical reading of the manuscript.