4.2 Professor in Groningen
55
was on strong recommendation of both Hendricus van de Sande Bakhuyzen
from Leiden and Jean Oudemans from Utrecht. The appointment followed by
Royal Decree in December. For Kapteyn, this must have come as a complete
surprise. Kapteyn accepted his appointment as professor on February 20, 1878
with an inaugural lecture, after taking an oath of loyalty to the King (Willem
III) and his formal admittance to the Senate of the university (the collected
professors). The text of Kapteyn’s inaugural lecture has not been preserved; we
only know the title from the university reports, namely The annual parallaxes of
the fixed stars. Very appropriate, because distances and the spatial distribution
of the stars were the subjects on which Kapteyn would continue to focus his
research throughout his career. The distances of stars were also the subject of
one of the propositions attached to his PhD thesis in Utrecht.
4.3 Without an Observatory
Kapteyn immediately went to work; to begin with, he attempted to obtain
an observatory in Groningen. Already three days after his appointment, there
was a meeting of the Senate, during which an request was approved for the
provision in the budget application that was to go to the Minister. The list
of desiderata was long, with ten items for the Faculty of Mathematics and
Natural Sciences. Kapteyn’s observatory was the third priority. The costs were
estimated at 14,000 guilders, which in current purchasing power amounts to
some 150,000 e. A physics laboratory (85,000 guilders) and a mineralogical
museum and laboratory (5000 guilders) were higher on the list. The budget
for the construction of an observatory, however, did not include the land and
instruments, which would have to come separately from special subsidies. The
following items were mentioned for the observatory:
Guilders
heliometer
19,200
clock
1,000
chronometer
500
universal instrument
400
prism binocular with stand 200
We have encountered the heliometer before: this is a telescope of which the
objective lens is cut in two, and where the two halves can move independently.
In this way, two stars and their distance (the angle on the sky) can be measured
from the amount of rotation between the two lens halves. A universal instru-
55
was on strong recommendation of both Hendricus van de Sande Bakhuyzen
from Leiden and Jean Oudemans from Utrecht. The appointment followed by
Royal Decree in December. For Kapteyn, this must have come as a complete
surprise. Kapteyn accepted his appointment as professor on February 20, 1878
with an inaugural lecture, after taking an oath of loyalty to the King (Willem
III) and his formal admittance to the Senate of the university (the collected
professors). The text of Kapteyn’s inaugural lecture has not been preserved; we
only know the title from the university reports, namely The annual parallaxes of
the fixed stars. Very appropriate, because distances and the spatial distribution
of the stars were the subjects on which Kapteyn would continue to focus his
research throughout his career. The distances of stars were also the subject of
one of the propositions attached to his PhD thesis in Utrecht.
4.3 Without an Observatory
Kapteyn immediately went to work; to begin with, he attempted to obtain
an observatory in Groningen. Already three days after his appointment, there
was a meeting of the Senate, during which an request was approved for the
provision in the budget application that was to go to the Minister. The list
of desiderata was long, with ten items for the Faculty of Mathematics and
Natural Sciences. Kapteyn’s observatory was the third priority. The costs were
estimated at 14,000 guilders, which in current purchasing power amounts to
some 150,000 e. A physics laboratory (85,000 guilders) and a mineralogical
museum and laboratory (5000 guilders) were higher on the list. The budget
for the construction of an observatory, however, did not include the land and
instruments, which would have to come separately from special subsidies. The
following items were mentioned for the observatory:
Guilders
heliometer
19,200
clock
1,000
chronometer
500
universal instrument
400
prism binocular with stand 200
We have encountered the heliometer before: this is a telescope of which the
objective lens is cut in two, and where the two halves can move independently.
In this way, two stars and their distance (the angle on the sky) can be measured
from the amount of rotation between the two lens halves. A universal instru-