  We give the detale description from various points of view of Pascal
automorphism,--- a natural transformation of the space of paths in the Pascal
graph (= infinite Pascal triangle), and describetha plan of the proof of
continuiuty of its spectrum. If we realize this automorphism as the shift in
the space of 0-1 sequences, we obtain a stationary measure, called the Pascal
measure, whose properties we study.
  The transformations generated by classical graded graphs, such as the
ordinary and multidimensional Pascal graphs, the Young graph, the graph of
walks in Weyl chambers, etc., provide examples of combinatorial nature from a
new and very interesting class of adic transformations introduced as early as
in \cite{V81}; some considerations by V. I. Arnold also lead to such
transformations. We discuss problems arising in this field. This is the first
paper of the series of articles about adic transformations.
