11.7 The Spatial Distribution of the Stars
243
purpose, procedures were already developed by Schwarzschild in Potsdam and
by (Ritter) Hugo Hans von Seeliger. The latter (see Fig. 11.7) we met earlier
as one of the candidates for the position in Groningen to which in the end
Kapteyn was appointed. A few years later von Seeliger had become professor in
München and director of the Sternwarte there. His career was mainly devoted
to the same problem that Kapteyn was working on, but his approach was much
more mathematical. He and Kapteyn were very different characters who had
little in common; although they must have known about each other’s work,
they communicated little. The mathematical approaches of Schwarzschild and
von Seeliger were fundamentally different. Willem Johannes Adriaan Schouten
(1893–1971) wrote a PhD thesis in which he compared the two methods. He
was not a paragon of diplomacy; Schouten completely disagreed with von
Seeliger’s approach and presented that it in a rather antagonistic way. Kapteyn
allowed the defense to go ahead in 1918, but gave the work of Schouten as
little publicity as possible. Nevertheless, it seems to have had an unfavorable
effect on the relationship between Kapteyn and von Seeliger. Schouten also
became a teacher at an HBS.
Fig. 11.7 (Ritter) Hugo Hans von Seeliger. This picture comes from the Album Amicorum,
presented to H.G. van de Sande Bakhuyzen on the occasion of his retirement as professor
of astronomy and director of the Sterrewacht Leiden in 1908 [47]