In 1837 Kaiser became director of the observatory which was still locatied in the academy building. His predecessor Prof Uylenbroek went to Physics. Kaiser was shocked by how neglected the facility ¹⁾ was and decided he wanted a new building. His main motivation for building a new observatory was that he wanted to have a facility that could compete with other facilities in the world. The fact that in 1853 the plans for a new observatory in Utrecht were announced, motivated him even more. It was unthinkable that Utrecht would become the center of astronomy as opposed to Leiden! However, he had no money to fund his plan. Luckily, Kaiser was a great public speaker and after some lobbying and personal audiances with members of the 'Tweede kamer', he soon convinced them that building a new observatory was crucial for the scientific community in the country. He studied the plans of most major observatories and eventually decided the observatory should be modeled after the Imperial Observatory in St. Petersburg which was build in 1839.²⁾

The Imperial Observatory had a central main building ³⁾, flanked by two wings connected by large rooms with in each of them transit circles. On the roof of the main building two domes can be found with mountings that are structurally separate from the main building.

One year later Kaiser published his plans in a book; 'De Inrigting der Sterrewachten, beschreven naar de Sterrewacht op den heuvel Pulkova en het ontwerp eener Sterrewacht voor de Hoogeschool te Leiden.' Where he explained that he wanted to copy the Pulkova observatory. This new observatory would cost about 112.500 guldens, six times more than the Sonnenborgh observatory. This, in combination with the fact that a copy of an imperial palace did not exactly sound modest, did not exactly motivate the government to help. However, using his outreach talent Kaiser gathered 26000 guldens with use of crowd funding, the sale of books and other outreach activities. (Which was about 1/4th of the needed sum and more than the Utrecht observatory had cost in total.) This combined with his silver tongue was enough to convince the government to fund the observatory in 1857. []

With the money in his pocket, we went out to look for a place to build it. His eye fell on a piece of land outside of the city. (Where Noordeinde and the Wittesingel meet, not occupied by the Haagweg parking space.) However this land was too expensive, so he could not buy it. Which was quite fortunate, as in 1878 a rail track was built there, which would have disrupted all measurements.

Kaiser once more used his problem solving skills and found a new location for the observatory, the Blue Bastion. This land belonged to the university and was free to build on, however it was part of the Hortus Botanicus, which was not very keen on giving away a large chunk of its land. However, in 1857 Kaiser became rector magnificus of the university and used his new found power to put a lot of pressure on this dispute. In one of his letters to the board of curators of the university he wrote: 'Ieder die in den vorigen zomer door den Hortus heeft gewandeld, moet echter bij zichzelven de opmerking hebben gemaakt, dat het personeel voor de onderhouding van den geheelen Hortus te kort schiet, of dat de Hortus voor zijn doel te groot moet wezen.' which roughly translates into; 'Anyone who has walked trough the Hortus last summer, has had to have noticed that there is not enough staff to tend to the entire garden, or that the Hortus is too large for its purpose.'[]

The only resistance that this plan had was that of W.H. de Vriese, the professor of botany. Fortunately he left to the Dutch Indies in that year and was replaced by W.F.R. Suringar, a 25 year old rookie who was promoted just 6 months before. Kaiser and his supporters had little trouble with surpassing him and finalizing the plan. It is said that Suringar was furious about having to let go about a quarter of the land, only to hear Kaiser complain that it was a very small chunk after all. Kaiser never meant to offend this man however, he just did not understand how astronomy could stand in the shadow of botany.

In 1858 the construction of the observatory had begun. The architect H.F.G.N.Camp (1821-1875), the man who had also designed the academical hospital⁴⁾ and the Kamerlingh Onness Laboratory. Kaiser would constantly squabble with the architect, who failed to see the importance of function above design and looks. In 1860 the building was done, however the construction had cost a whopping 131.845 gulden, more than was asked by Kaiser. This left no money for instruments. However with help of Kaiser and his successors, the building was expanded many times.

In 1861 the observatory obtained the meridiaankijker, togehter with the 6“ this was enough to officially open the observatory. That's why there is a year between the completion of the building and the opening.

The inside of the building would be decorated with fake marble, these marbleized walls actually cost more than real marble would have cost, as everything is hand painted by a professional marbleizer. The walls now are reproductions of how they used to look, again all handpainted, but a few small patched of the original 'marble' are still visible. [] []

[]

[] In 1861 the 6'' was installed in the small dome and the 7'' was installed in the large dome. The roof of the observational room (now Kaiserroom) could be opened. Here astronomy students could practice observations without troubling the scientists in the domes. Before the library was made as such, the room was used by the Verification Bureau of Government Instruments, in practice navy instruments. Kaiser became “verificateur” in 1858, his son Pieter J. succeeded him after his death. Later a special room was added to the front of the main building, just left of the entry to the old lecture room. The Verification Bureau had evolved into the MEOB, and is now located in Den Helder, which is now again merged with the Marine. In the entry hall there, the bust of Kaiser had a prominent place. It is exactly the same as the one which stands in the hall of the observatory. It is in fact the original gypsum mold, which had to be destroyed but turned up at a flea market, and was recognized there. The bust can now be seen in the Marine Museum of Den Helder.

The national time service was originally coupled to the “Verification”. The clock Hohwü nr. 17 was controlled by the meridian circle . Starting in 1858, on Tuesdays and Fridays, a time synchronization signal was sent by telegraph to harbors in Vlissingen, Hellevoetsluis, Willemsoort (navy) and Amsterdam (merchant). Later more locations were added: the weather affiliations of the KNMI in Rotterdam and Amsterdam, the public timeservice in Leiden, and all telegraph stations. This service came to an end on april 1st 1921, when a radiostation on top of the Eiffeltower took over. The visitors center (BZC) is housed in the former service rooms of the directors’ home. No cooking or laundry could be handled upstairs. Only the nanny had a room there. The current entry was meant for personnel and suppliers. The current connection, from the BZC to the foundation of the meridian circle, was not there. The corridor which is there now was excavated during the restoration. The visitors’ desk is located in the former kitchen.

Several buildings came and went. A house for observers was erected on the site of the current Photograph. Next to it, around the turn of the former century, there was cottage for a gas generator to recharge the accumulators. This ended when the municipal power net became reliable enough. Also, for some time, there was a blacksmith shop on a the current parking lot.

In the garden there were two observation huts. The “Talcott hut” for monitoring the polar motion. And a hut in front of the 6” entry for a transit instrument. Only the former survived the renovation to become a tea-house. [][][] [][]

[]Frederik Kaiser dies. In honor to his life, students gather money to make a bust.

The Heliometer tower was added in 1878. The architect was Petrus J.H. Cuypers who also built the Central Station and the Rijksmuseum in Amsterdam. It is a simple tower in Neo-Dutch renaissance style, but one of the few buildings of Cuypers in Leiden. Originally it had a cylinder/conical dome. In the original drawings the top of the tower was decorated with various constellations, but Bakhuyzen, the director did not agree to that.

Cuypers also designed the library interior, added later, as is visible in the somewhat awkward connection to the windows. [][]

Somwhere between 1875 and 1907⁵⁾ Leiden started to outgrow its borders and soon the other side of the Wittesingel started to get urbanized. People at the observatory were not thrilled by this development, as this would mean that the horizon of the meridiankijker would be affected. After a lot of lobbying with a peoples committee led by Prof. Oort (not the astronomer but his grandfather, professor of theology) a agreement was settled. For 14000 gulden (An enormous sum) the strip of land in the meridiaankijker's field of view would stay as it was. This strip is still visible in maps today. [] []

[]The smaller East and West domes were added in 1922. The style of the architecture is eclectic, but has an inclination to neoclassicism.

In the run-up to the second world war air-raid shelters were erected in the cellars of the observers house. The reinforced ceiling is still visible there, as well as an extra exit to the garden. During the war people were in hiding in the crawl-space accessible behind the BZC toilet area. During the war the illegal journal “Trouw” was printed in the (cottage)house at nr. 2. Hertzsprung certainly was aware of this.

[]The second free standing tower houses the Photographic telescope. Originally this instrument was housed in a building about 40 m down the Sterrewachtlaan. The offices and dome were the domain of Hertzspung when he arrived to start the “astrophysics” department. In 1960 the current tower was erected.

In 1970 the building got the status of national monument.

The Sterrewacht moved to the Huygens building. [source?]

The Sterrewacht moved to the Huygens and Oort buildings in 1997. (Oort building was added)

[]announcement_renovation.jpgThe (now) “Oude” Sterrewacht, was renovated between 2009 to 2012. The money for the renovation was partially obtained by the sale of the land east of the observatory, here houses will be built.

Pictures of renovation here

It became a lecture building for law students and post-academic courses (PAO). The visitor center, in the souterain of the former directors house, is part of the Hortus but operated by the Sterrewacht. The terrain around the observatory is again integrated in the Hortus and the pedestrian path around the old ramparts. Observatory garden The old instruments in the domes are maintained by amateurs (Werkgroep Leidse Sterrewacht). Renovation|

[]New housing plans were made for the land sold east of the observatory. More info here