Rudjer Boscovich (1711, Dubrovnik - 1787, Milan) Rudjer Boscovich is one of the greatest minds of 18th century. His works in the fields of mathematic, physic and astronomy made him world famous already at his lifetime. Theoria Philosophie Naturalis, 1758, is his most important and noted work. Rudjer Boscovich, a physicist, a mathematician, an astronomer, a philosopher and a diplomat was born in Ragusa, now Dubrovnik, Croatia on May 18, 1711 and died in Milan, Italy on February 13, 1787. When he was fifteen he joined the Jesuit Order. He studied in Dubrovnik and later on at the Collegium Romanum in Rome. After his studies he started to lecture there to come to the position of the professor of mathematic at the same university. 1736 is the starting year of his dissertations and scientific discussions in mathematic, machinery, astronomy and geodesy. The first one, On the Sunspots, called for attention of learned men of the time. Every further discussion, mainly on the applied mathematics confirmed him as the world-class mathematical genius. At his time meridians were measured to get the precise idea of the shape and size of the earth and Pope Benedict XIV commissioned him and his fellow Jesuit, Ch. La Maire, to carry out several precise meridian arc measurements between Rome and Rimini. It also seems to have been due chiefly to his influence that the same pope, in 1757, decided to leave out the decree of the Index against the Copernican system. Boscovich, according to the views expressed in earlier essays, namely De materiae divisibilitate et du principiis corporum dissertatio (1748); De continuitatis lege et ejus consectariis pertinentibus ad prima materiae elementa eorumque vires (1754); De lege virium in natura existentium (1755); Philosophiae naturalis theoria redacta ad unicam legem virium in natura existentium (1758), held that bodies are composed of innumerable structures with repulsion existing between them. This repulsion is due to forces within these elements. It tends to become infinite when they are in very close proximity, whereas within certain limits it diminishes as the distance is increased and finally becomes an attractive force. This change is caused by the diverse direction of the various forces. This theory enabled Boscovich to cleverly work out mechanical laws of bodies (extension, cohesion) as well as chemical and physical ones. In autumn 1759 Boscovich goes to France and in May 1760 he goes to England where he becomes Fellow of the Royal Society for which he writes Carmen de Solis ac Lunae defectibus (5 vol.) In 1761 initiates the observation of the approaching transit of Venus. He later travels to Poland and Constantinople and in 1784 publishes A Journal about it. After his return from Constantinople, in 1764 he is appointed professor of mathematics at the University of Pavia. In 1770 Boscovich is invited to Milan, where the governor of Milan, count Firiman establishes for him the Department for optics and astronomy. He took active part in the founding of the observatory in Brera, which was erected in 1765 according to Boscovich's plans and is, even in our own time, among the most prominent of Italy. Due to the later conflicts with another Head of the Observatory, Viennese court released Boscovich of his duties. Feeling wronged, he resigned his professorship at Milan in 1773, and left for Venice. In 1772 after cutting his connections with the observatory, Louis XV asked for his services and invited him to Paris, where a new office, Director of Optics for the Marine, with a salary of 8,000 francs, a whole fortune for that time, was created for him. Boscovich was highly praised by his followers Lalande, La Condamine, Messier, and Clairaut, but his wealth and privileges, his personal sensitivity, the court intrigues and polemics with astronomer Laplace about working out the paths of meteors, and the physicist Rochon regarding priority in the invention of the rock crystal prismatic micrometer, brought about reservations in some French encyclopaedists, namely D'Alembert. Some have ascribed the invention of the micrometer to the Dutch natural philosopher Huygens with no reason. Its advantage, as Boscovich says in his memoir "De novo telescopii usu ad objecta coelestia determinanda" (Rome, 1739) lies in its not requiring any artificial illumination of the field of the telescope. This makes it useful in observing faint objects, Boscovich clearly points out in connection with the comet of 1739. His health deteriorated and in 1782 Boscovich leaves for Bassano, Italy, where in 1783 - 85 he publishes five volumes of his work on optics and astronomy (Rogerii Josephi Boscovich opera pertinentia ad opticam et astronomiam). Shortly after that, in 1786, he moves to his Brera, hoping to continue his work, but he dies soon of pneumonia. He is buried in the church of Santa Maria Podone Boscovich was a versatile and hard working mind. Besides things mentioned above, he also carried out the draining of the Pontine marshes at Rome in 1762, planned repairing the alarming fissures in the cupola of the Milan Cathedral, as well as reinforcing the delicate dome of Saint Peter's Basilica, and occupied himself with the archeology of Troy while being in Constantinople. Though he visited his birthplace, Dubrovnik, only once in his life (1747), he kept close contact with it, carrying out important diplomatic missions for it, and never forgot its mother tongue, which is seen from his private letters to his family. The research oh Boscovich's work is more and more common. They show his conceptions are real whether they be foretelling or inspirations for contemporary thinking, especially in philosophy, physics or other natural sciences. Boscovich knew Newton and his work very well and was one of the first to accept his viewpoints on gravitation, but he did not follow his theories. His atomism (forces between points attracting on greater distances and repulsing on shorter ones) thus overcoming the Newton - Leibnitz dispute, opened new hypothesis about microcosms leading to Kant later. Such thinking had great influence on physicists such as Thomson-Kelvin and Faraday. Resuming the work of Boscovich we must bear in mind that, besides being an excellent explorer in the field of astronomy, machinery, optics and geodesy, he was also a careful investigator whose test were conducted with strict logical thinking of a scientific mind. His open-mindedness enabled direct scientific experience to be transferred to the new natural system freed of Newton's ideas of absolute space. These facts lead Nietzsche to compare Boscovich's work with Copernicus. All of these put Boscovich among the small number of great human minds whose conceptions, even when not closely followed, represent unavoidable steps in the development of human spirit. His other works: The Aurora Borealis (1738); The Application of the Telescope in Astronomical Studies (1739); The Various Effects of Gravity (1741);