Preface
xiii
Fig. 0.2 Kapteyn had his loose publications bound as three volumes and numbered
the resulting pages sequentially. In the fourth (red) volume, bottom right, he
collected publications by himself and others on the Star Streams. These volumes
reside in the Kapteyn Room of the Kapteyn Astronomical Institute. Photograph by
the author
Persons are identified in this book by their full names and years of birth
(and death when applicable) the first time they are mentioned. This then also
is the first reference to that person in the Index. As in my English biography I
refrain from using nicknames, such as ‘Dody’, ‘Hetty’ and ‘Rob’ for Kapteyn’s
children, as I feel this should be restricted to intimates.
Numbers between square brackets refer to literature sources or to
Websites in the section References. Comments on these are in footnotes, but
I tried to keep these to an absolute minimum not to interrupt the reading of
the main text unnecessarily.
Genealogy. There are a number of useful Websites for family tree research,
certificates or family messages. The ones I have used have been collected in
Refs. [11]–[17].
Currency calculators. To convert currencies from other times or countries
into Euro’s of the present time (at least indicatively), I have used Websites,
which have been collected in Refs. [18]–[20].
Geographical locations. For a map of the Netherlands in Kapteyn’s days
and the location of cities and other places that play a role in the book, see
Fig. 1.0.
xiii
Fig. 0.2 Kapteyn had his loose publications bound as three volumes and numbered
the resulting pages sequentially. In the fourth (red) volume, bottom right, he
collected publications by himself and others on the Star Streams. These volumes
reside in the Kapteyn Room of the Kapteyn Astronomical Institute. Photograph by
the author
Persons are identified in this book by their full names and years of birth
(and death when applicable) the first time they are mentioned. This then also
is the first reference to that person in the Index. As in my English biography I
refrain from using nicknames, such as ‘Dody’, ‘Hetty’ and ‘Rob’ for Kapteyn’s
children, as I feel this should be restricted to intimates.
Numbers between square brackets refer to literature sources or to
Websites in the section References. Comments on these are in footnotes, but
I tried to keep these to an absolute minimum not to interrupt the reading of
the main text unnecessarily.
Genealogy. There are a number of useful Websites for family tree research,
certificates or family messages. The ones I have used have been collected in
Refs. [11]–[17].
Currency calculators. To convert currencies from other times or countries
into Euro’s of the present time (at least indicatively), I have used Websites,
which have been collected in Refs. [18]–[20].
Geographical locations. For a map of the Netherlands in Kapteyn’s days
and the location of cities and other places that play a role in the book, see
Fig. 1.0.