French visitors to Hevelius’ observatory

In his youth Johann Hevelius visited many European countries, including France. There he possibly met Marin Mersenne and Ismael Boulliau, and certainly Pierre Gassendi and Athanasius Kircher. Later, for decades, it was Pierre Des Noyers (1606–1693), a secretary of Queen Louise Marie Gonzaga, who played a very important role in the astronomer’s contacts with French scholars and with both French and Polish royal courts. Des Noyers certainly made his first visit to Hevelius’ observatory at the beginning of 1646, when Louise Marie, the new queen of French origin, arrived in Poland. This visit gave rise to many personal contacts, a lively correspondence and collaboration between Des Noyers and Hevelius. In 1648, a group of envoys led by Count Louis d’Arpajon came to the Polish-Lithuanian Commonwealth, and they stayed in Gdańsk (Danzig) for a long time. They made the acquaintance of Hevelius; especially among them François Bernier (1620–1688), a student and long-time companion of Gassendi, later the author of an important outline of his philosophy. Bernier returned to France via Italy where, at Hevelius’ request, he purchased for him lens glass in Murano near Venice. Years later he again rendered a service to Hevelius: Bernier’s account of Hevelius’ observatory helped to place in 1663 the Gdańsk astronomer among the scholars financially supported by Louis XIV (with an annual pension paid to him for nine years). Consequently, Hevelius dedicated two of his works to Louis XIV: Cometographia (Gdańsk 1668) and Machinae coelestis pars prior (Gdańsk 1673). Hevelius, like Tycho Brahe before him, had the opportunity to play host to crowned heads at his observatory and his home. During the negotiations in Gdańsk for the Peace Treaty of Oliva, King John Casimir and Queen Louise Marie visited Hevelius. It was then that Des Noyers watched with admiration the astronomer’s sophisticated observatory, which in those days was the largest observatory in Europe. In 1661, on his way to the Polish royal court in Warsaw, Ismael Boulliau (1605–1694), a famous French astronomer and “political scientist”, stopped at Hevelius’ place and stayed there for quite a long time. The two astronomers carried out joint observations. In his letters, written from Gdańsk, Boulliau admired the instruments built by Hevelius and his efficacy in using the instruments. Later, the two exchanged dedications to each other in their published papers. Yet, “Fig. W” in Hevelius’ Machinae coelestis pars prior (Gdańsk 1673) does not portray Boulliau, as some claim, but an astronomer’s assistant. In Autumn 1663, two brothers – Armand and Antoine de Gramont, the sons of Marshal de Gramont, who fought in King John Casimir’s military campaign against Moscow – visited Hevelius’ observatory. Hevelius mentioned their visit in one of his letters. In the early 1670s, Des Noyers stayed in Gdańsk for a longer time. He left for Warsaw during the reign of Michał Wiśniowiecki who appeared to be hostile to France. In his letter to Boulliau Des Noyers described receptions in the astronomer’s house and observations he made together with other learned people from Gdańsk. When he came again from France in late 1679, Des Noyers was a sad witness to results of the tragedy that had struck Hevelius in September of that year, when his house and his observatory were burnt in a fire. Des Noyers and Boulliau mourned in Paris at the news of the disaster and at the possible loss of the manuscripts of unpublished Hevelius’ works. Luckily, those had survived. However, the astronomer’s sophisticated instruments had perished in the fire. That was why, visitors from France who followed had no longer a chance to see famous Hevelius’ instruments. In Autumn 1681, Jean Francois Regnard (1655–1709), in later years a well-known poet and author of comedies, visited Hevelius. Subsequently, he reported his discussions with Hevelius and presented him as a great supporter of the Copernican theory. Undoubtedly, French envoys and courtiers, such as Vaubreuil and Darcy, visited Hevelius on their way to the Polish court via Gdańsk. Through them Hevelius sought – unsuccessfully – to renew his pension from Louis XIV. The King of France gave him only a one-time subsidy in the aftermath of the fire. At an unspecified time Hevelius was visited by François Paulin Dalerac, a courtier of Queen Maria Kazimiera; this visit is mentioned in Dalerac’s memoirs. Maria Kazimiera, unmarried at that time, might have accompanied Louise Marie during her visit to Hevelius’ observatory. No records are available to prove that she visited Hevelius as another French queen of Poland. Her husband, John Sobieski, visited Hevelius’ place many times and took part in observations, first while a Marshal and later as the King of Poland, Jan III (John III). All in all, we can name ten persons as conclusively identified French visitors to Hevelius. Among them there were one queen, two warrior-aristocrats, two diplomats, one courtier, one poet and three scholars