the Observatory. His assistant Johann Heinrich Hoffmann moved up to replace him as the head of the observatory. After his death in 1716 Christfried Kirch, the son of Gottfried Kirch, became his successor. He was aided in his work on the calendar by his mother Maria Margarethe Kirch and his sister, just like he and his mother once helped his father. His mother died in 1720. From 1720 until 1736 he was assisted with the practical activities by J. G. Schütz. After the death of Christfried Kirch he took on the post of director in 1740. For many years the calculations for the calendar were continued the most part by Christine Kirch; she was also responsible for the keeping of the accounts. During the years of "Old Observatory" questions of astronomy were also discussed and grappled with in Berlin by the likes of, among others, Leonhard Euler, Joseph Louis Lagrange and Johann Heinrich Lambert. In 1765, Giovanni_Salvemini (aka Johann Castillon) received the position of First Astronomer. In 1768, the Observatory received a mural quadrant constructed by John Bird, their first really important observing instrument. This device can now be seen in Babelsberg Observatory. Johann III Bernoulli served from 1764 to 1787 as Director of the Old Observatory and was succeeded by Johann Elert Bode. Lambert fetched Bode to Berlin in 1773, in order to publish an almanac; after Lambert' death, Bode became the sole editor. The first edition of the Berliner Astronomisches Jahrbuch (for 1776) had already appeared by 1774, initiating the longest-lasting publication series in astronomy, lasting until 1959. By virtue of this medium, Berlin Observatory developed into an information source of prime importance within Europe. Originally Bode had the venerable Christine Kirch to assist him with the work on the calendar. In 1774, he married a granddaughter of one of her sisters; she was likewise entrusted with astronomical work in line with the Kirch family tradition. Christine Kirch died in 1782. As director of the observatory, Bode was able, through favors from Frederick William III of Prussia, to extend the till then rather third-class-equipped institution with a second observing level. When Bode entered a petition to this effect on 2 November 1798, space for observing within the tower was still limited to the third storey. The two storeys over it were united to a single spacious level. From there, the observing activities could be extended, once the calculated