I visited the National Astronomical Observatory of Japan, Mitaka campus, today. It's now mainly a research institute, the main telescopes are in the mountains and in Hawaii, but they have some of the old telescopes, still working. Originally, the NAOJ was located in Azabu, central Tokyo, where it was founded in 1888. After the Kanto Earthquake of 1923, the worst in Japanese history*, the Observatory was persuaded to move further out, to Mitaka in the west of Tokyo.
Here is the original Mitaka Observatory Dome:
How it looked today:
The telescope was installed in 1927. A 20cm Achromat, of 359cm focal length, it was built by Carl Zeiss of Germany. The mount is driven by a clock mechanism, with governor and weight, allowing tracking without electrical power for about one and half hours.
It's a lovely thing.
One of the staff demonstrated moving the dome, and tracking the sun.
The scope was mainly used for solar observation from 1931. Between 1939 and 1999, astronomers noted the sunspot activity and reported it to other institutes all over the world.
Moving on, down a tree-lined path with appropriate ornaments:
We come to this much bigger, and quite promising, dome:
Built in 1929, it houses a 65cm refractor of 10m focal length, also of Carl Zeiss manufacturer. Entering via the newer square building at ground level, through to the original structure, witness the huge flared support going through the suspended floor and into the ground. This has to carry a very large scope...
Like it's smaller neighbour, the mount is mechanically controlled with gears, weights and pulleys :
When you walk upstairs to the observatory floor, you can see what all the engineering is there for ...
(more...)
*For fatalities. On 1 September 1923, the Great Kanto earthquake measured magnitude 7.9. The collapse of buildings and subsequent fires killed over 100,000 people. On 11 March 2011, the Great East Japan earthquake measured magnitude 9.0. Recording ground acceleration of 2.7g, it moved NE Japan almost 3m closer to America. The tsunami that followed reached over 40m in height and up to 10Km inland. Confirmed deaths were close to 16,000. An additional 1/3 million people lost their homes.