the late 19th century in working condition: the 270 mm refracting telescope, built in 1884, to which a 156 mm astrograph (now used with modern CCD imagers) was added in 1890; the 132 mm meridian circle, the largest meridian passage instrument of the Austro-Hungarian Empire; its ancillary vertical circle instrument, one of the few that still exist at European observatories; and the 217/3000 mm heliometer, the largest of its type that was ever built. The heliometer was designed for measuring tiny distances, and could be used for measuring the distance to other stars by trigonometric parallax. The instrument was installed in 1896, an by 1910 it had computed 16 parallax distances to other stars, out only 108 total known to science at that time. The meridian circle (i.e. transit-type instrument) can record the locations of the things in the sky, and also be used to calculate a local time. The instrument type was very important in the old observatories, and had to do with time, the geography of the Earth, and the location of things in the sky. The great refractor is a double telescope, with a primary of 270 mm (27 cm) aperture objective lens, and was built by Repsold and also Steinheill; it was installed at the observatory in 1886. The observatory also has some other astronomical instruments, and an Urban No.18 pendulum clock. The clock would often be used in conjunction with other astronomical instruments. Current research Besides its function as a scientific museum and its ongoing mission concerning popularization of astronomy, the Kuffner observatory serves as the Austrian national host for the INES (International Ultraviolet Explorer New Extracted Spectra) database. It hosted the Meeting on Asteroids and Comets in Europe (MACE) in 2006, and the DARKSKY European Symposium, an event of the Dark-sky movement, in 2008. The current director is the Austrian physicist and author Werner Gruber. Architecture See also List of astronomical observatories List of astronomical societies Lists of telescopes References External links Report on the DARKSKY 2008 European Symposium Buildings and structures in Ottakring Astronomical observatories in Austria Public observatories Science and technology in Austria Buildings and structures in Vienna Education in Vienna Museums in Vienna Science museums in Austria Double telescopes