  We present an original method of digitizing and astrometrically reducing
"Carte du Ciel" plate material using an inexpensive flatbed scanner, to
demonstrate that for this material there is an alternative to more specialized
measuring machines that are very few in number and thus not readily available.
The sample of plates chosen to develop this method are original "Carte du Ciel"
plates of the San Fernando zone, photographic material with a mean epoch
1903.6, and a limiting photographic magnitude ~14.5, covering the declination
range of -10 < dec < -2. Digitization has been made using a commercial flatbed
scanner, demonstrating the internal precision that can be attained with such a
device. A variety of post-scan corrections are shown to be necessary. In
particular, the large distortion introduced by the non-uniform action of the
scanner is modelled using multiple scans of each plate. We also tackle the
specific problems associated with the triple-exposure images on some plates and
the grid lines present on all. The final measures are reduced to celestial
coordinates using the Tycho-2 Catalogue. The internal precision obtained over a
single plate, 3microns ~ 0.18" in each axis, is comparable to what is realized
with similar plate material using slower, less affordable, and less widely
available conventional measuring machines, such as a PDS microdensitometer. The
accuracy attained over large multi-plate areas, employing an overlapping plate
technique, is estimated at 0.2".
