1904. In 1920, the Observatory started transmitting the exact time by radio signals. The observatory participated in the basic geodesic work, namely in measuring degrees of the arc of the meridian from the Danube to the Arctic Ocean (until 1851), and in triangulation of Spitsbergen in 1899–1901. Military geodesists and hydrographers used to work at the Observatory as interns. The Pulkovo Meridian, which passes through the center of the main building of the Observatory and is located at 30°19,6‘ east of Greenwich, was the point of departure for all former geographical maps of Russia. In order to observe the southern stars that could not be seen on the observatory's latitude, the scientists organized two affiliated observing locations. One of them was an astrophysical station in the Crimean town of Simeiz (Simeiz Observatory), which had been organized on the basis of a private observatory presented to the Pulkovo Observatory by an astronomy lover N. S. Maltsev in 1908. The other was an astrometric station in Mykolaiv – a former observatory of the Department of the Navy, (today's Nikolaev Astronomical Observatory). Later history During the siege of Leningrad (1941–1944), the Observatory became the target of fierce German air raids and artillery bombardment. All of the buildings were completely destroyed. Under dramatic circumstances, the main instruments were saved and stored safely in Leningrad, including the lens of the destroyed 30-inch refractor, and a significant part of the unique library with manuscripts and important works from the 15th to 19th century. On February 5, 1997, nearly 1,500 of the 3,852 books were destroyed by malicious arson and the rest of the library items were damaged by flames, smoke or water. Even before the end of the war, the Soviet government made a decision to restore the Observatory. In 1946, it began the construction after having cleared the territory. In May 1954, the Observatory was re-opened, not only having been restored but considerably expanded in terms of instruments, employees and research subjects. New departments had been created, such as the Department of Radio Astronomy and Department of Instrument Making (with its own optical and mechanical workshop). The surviving old instruments were repaired, modernized and put into service once again. Also installed were new instruments, such as the refractor, a horizontal meridian device, a photographic polar telescope, a big zenith telescope, stellar interferometer, two solar telescopes, coronagraph, a big radio telescope and a variety of labware.