The preface is quite interesting and breathes frustration.
It mentions the founding of the Leiden Observatory, of which Kaiser became director, on October 1st, 1858.
After completion, the observatory was inaugurated in 1861.

Translation:
It will be pleasing to the friends of astronomy to learn that,
by the favorable decision of His Exc. the Minister of the Interior,
on the first of this month, the founding of an observatory in Leiden has actually commenced.
Since the year 1803, this founding has been under deliberation, and,
especially in recent years, it repeatedly seemed as if the impossible had to happen
to thwart all efforts made on its behalf by the noblest friends of science.
The expectations, so long disappointed, now finally seem about to be fulfilled,
and may Heaven grant its indispensable blessing upon it.
May the new observatory one day grant the fullest satisfaction
to all whose interested diligence gave it life.
May it, through the richness of its fruits, one day shame those
to whose opposition the delay of its founding must be attributed.
LEIDEN, the 25th of October 1858.
F. KAISER.