STORY OF SELF-MADE MIRROR AND OBSERVATORY

　　　　　Even now twenty years later since that time, as I am clearly able to recall, it was on Sunday in February l978, when I visited with my wife and son the planetarium at the west side of the Central Park in New York City, that I made up my mind to start taking photos of the wonders in the sky. Many beautiful color slides of planets, star clusters, nebulae and the like were displayed at the shop there, and enchanted me so far to remind me of the dream cherished in my mind when a junior high school boy.
At the time, based on the Sister City Agreement between the Tokyo Metropolitan Government and the City of New York, I was staying as a thirteenth exchange official to the City from the Government, and engaging in the investigation of the causes of fiscal crisis the City of New York had been fallen since 1975. (The result of that investigation was published as a book 'Financial Systems of Local Government in USA' in April 1989, about ten years later.
　　　　　After Coming back to Tokyo in April that year, I fortunately found a book 'Telescope Making' written in Japanese by Ken Yoshimochi at a bookstore in Tokyo. Consulting with this book, I made a 8 cm refractor, whose lens available in Tokyo was achromatic, with a vinyl tube and plywood board in August l978, and observed the Moon, the Jupiter, the Saturn, etc. But I found the telescope was not excellent enough for my heart content, compared with the beautiful slides mentioned above.
　　　　　In March l979, a mirror polishing course was held in Tokyo. At the course it took two days for me to complete a 10 cm reflective mirror made with Pyrex glass. This was the first step in the long course of mirror polishing by myself. After this mirror, a 15 cm, a 20 cm and a 25 cm were polished successively in a half year. An amateur astronomer among the participants of the course helped me build a equatorial telescope with the 25 cm and the 15 cm reflectors in the garden, and I could enjoy the splendors of the night sky and take their pictures. But the night sky in the suburbs of Tokyo is so bright that longer exposure than forty minutes was impossible even with a filter of R64 for cutting the brightness of the night sky.
　　　　　A ready-made 31 cm mirror blank made with Pyrex glass, however, was not so easy to polish and it made me work three or four hours after coming back from the office, three or four nights every week. It took 6 months to complete in the long run. The hard work, however, was fully rewarded, because I could enjoy watching the splendid views of the Moon's craters, planets, nebulae and galaxies and taking their photos. As a result of the necessity for photo processing, I built a small photo laboratory by myself in the garden.
The confidence resulting from the above experience, made me start polishing a custom-made 50 cm mirror blank called E6 produced by Ohara Inc. in March l982. The expansion index of E6 is a little less than Pyrex glass. The thickness and weight of the mirror blank were respectively 5 cm and 24 kg. For the purpose of polishing the mirror, I had to make a polishing machine for myself, consulting the three volumes of ''Telescope Making'', by Scientific American inc., issued in 198l. A Second hand lathe was introduced for polishing machine construction. To handle the lathe in order to make parts of the polishing machine was the first experience for me, as I had graduated from the law department of Tokyo University and not a professional mechanical engineer. Welding, drilling and tapping were interesting, but hazardous at the same time, and so careful handling was essential for preventing me from fatal injuries.
　　　　　During the term of polishing the mirror, I constructed an equatorial equipment in York style, namely a telescope without a mirror in this case, in the garden, for the purpose of testing the mirror surface. The Foucault test was useful and precise for a small mirror, but it had proved insufficient for testing such a big mirror as a 50 cm, judging from the experience of the 30 cm mirror. And so, I presumed it was necessary to observe star with the ongoing mirror directly without plating aluminum on the surface and to check carefully the half way of polishing.
　　　　　It was in July l984 that a self-made telescope with a 50 cm mirror, literally the fruit of my sweat, was completed after taking almost two years. The next barrier to pass over was the cost of plating the mirror with aluminum. A famous plating firm in Tokyo astonished me by telling that the cost was \400,000 ($3,300, l$ = l25 Yen), which was more expensive than the price \310,000 ($2,480) of the 50 cm mirror blank. Alter calling up many plating companies, I finally found out the Yamada Optical Inc., whose cost was only \25,000 ($200).
When the Halley's comet visited the Earth two years later, the telescope was introduced to the public through several TVs, newspapermen and magazine reporters as a self-made big telescope, which made my wife cease to complain about the telescopes though she didn't approve them.
　　　　　One yew before the Halley's comet came, the telescope with the 30 cm reflector and the 8 cm refractor, both made by myself as mentioned above, was donated to a junior high school in Ibaraki Prefecture where I studied an elementary course of astronomy, so that pupils and their parents might observe the comet.
At that time, the 50 cm reflector was the thirteenth biggest including the National Observatories in Japan. The next target was a one meter mirror, which would be the fourth biggest in Japan, and the biggest as a mirror polished by an amateur astronomer. I ordered Ohara Inc. a one meter mirror blank of E6 with thickness of 13.5 cm and weight of 230 kg in May 1987. The price was reduced from \4,000,000 ($32,000) to \3,000,000($24,000), because I persuaded the dealer by telling that I had enthusiasm enough for a big telescope and astronomy, but no money enough for a mirror blank.
　　　　　Making a new polishing machine, a big project for me, started the following month, and a temporary tower more than five metes in height for mirror test was constructed with steel pipes in the garden. Through try and error of two years and five months, the mirror with focus length of 3983 mm (F3.92) was completed on November 12 1989. The cost for plating the mirror by the Yamada optical inc. was \l00,000 ($800).
　　　　　What was the most difficult was to determine what was the perfect mirror, because to test such a big mirror was the first experience for me and also for those who were invited to test the mirror in Tokyo area, in spite of adopting the Ronchi test as well as the Foucault test. Saturday nights, it often became light in the morning, while I was being absorbed in the mirror test.
　　　　　I have been living in Mitaka City located about 15 km from the center of Tokyo since our marriage in 1964 when the Tokyo Olympic Games were held. As the night sky in Tokyo is too bright for such a big telescope, I had to choose a site where the night sky is dark and clear.
　　　　　In December 1993, I started building an observatory by myself also in this case, though I was already fifty eight years old at that time, on the Site 35l meters above sea level, with three thousand square meters, bought from the Kita-ibaraki City on the promise of opening to the public after the completion of the observatory. High on the mountain we can command a spacious view of the Pacific Ocean.
　　　　　It was dangerous to cut down the coppice with a chain saw, and sweaty at the same time. I tried to do by myself everything I could do, from concreting to making parts of equatorial equipment. Five prefabricated laboratories of three by six meter in width for machine, mirror polishing, photo developing, data and book storage, and one of three by twelve for celestial photo exhibition were built in the site. Three moving garages on rails, for the personal computer-controlled one meter reflector, 50 cm and six smaller telescopes, were constructed by the assistance of many volunteers. A six by nine meter lodge room] for ten observers and a fireplace was built for my stay and also accommodation of amateur astronomers.
　　　　　The Observatory is located about 200 km to the north from Tokyo and it takes around three hours to arrive there by car. Every Saturday morning, starting at 5 am by car from Tokyo, and arriving around 8 am at the site, passing through traffic jam in central Tokyo, I worked for construction of concrete structure, lodge, light steel houses, etc. until l0 p.m. or so. Getting up early at 6 am next morning, and starting to work in the same way as above, the work continued until the evening of Sunday, and I came back to my home in Tokyo around l0 p.m. My wife went there sometimes and helped me in cooking.
　　　　　The view of the Andromeda galaxy (M31) through the one meter reflector is overwhelming and we can enjoy the slight pink color of the Orion nebula (M42), though the climate in Japan is not in favor of the observatory, in short we seldom have clear night skies.
　　　　　The total money spent for the telescopes during about twenty years, is approximately 25 million Yen (US$200,000), which will sound either big or amazingly small to the readers, though I can't imagine precisely, considering the aperture of the telescope mirror. This sum is not impossible, however, for an average office worker in Japan to spend for his hobby during such a long term as twenty years. In any event way, I believe I have proved that everyone can construct an observatory, if he or she will be able to accept such a long laborious undertaking by himself or herself on the basis of the spirit of do-it-yourself.
　　　　　As of April 1998, the Observatory is almost completed, but the improvement work will be continued as long as I am active. In the near future I will be able to be in contact with the readers through the world wide network（http://www2u.biglobe.ne.jp/~yamaobs）. Full-scale observations in the form many volunteers can take part in, will be performed from now on. Visitors from abroad will be welcome.