1.
Johann III Bernoulli
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Johann III Bernoulli, grandson of Johann Bernoulli, and son of Johann II Bernoulli. He was known around the world as a child prodigy and he studied at Basel and at Neuchâtel, and when thirteen years of age took the degree of doctor in philosophy. When he was fourteen, he got the degree of master of jurisprudence, at nineteen he was appointed astronomer royal of Berlin. A year later, he reorganized the observatory at the Berlin Academy. Some years after, he visited Germany, France and England and his travel accounts were of great cultural and historical importance. On his return to Berlin he was appointed director of the department of the academy. His writings consist of travels and astronomical, geographical and mathematical works, in 1774 he published a French translation of Leonhard Euler’s Elements of Algebra. He contributed several papers to the Academy of Berlin, and in 1774 he was elected a member of the Royal Swedish Academy of Sciences. He was entrusted with the Bernoulli familys mathematical estate, also, his correspondence,2,800 items, were sold to the Steckholm Academy until they were found by Gylden at the Stockholm Observatory in 1877. He is one of the last notable members of the Bernoulli family and this article incorporates text from a publication now in the public domain, Chisholm, Hugh, ed. Bernoulli

2.
William Otto Brunner
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William Otto Brunner was a Swiss astronomer. From 1926 until 1945 he was the director of the Swiss Federal Observatory and he continued the series of Zurich sunspot observations that was begun in 1864 by the observatory founder, Rudolf Wolf. The crater Brunner on the Moon is named after him, Brunner, William, Die Welt der Sterne, Zurich,1947. Brunner, William, Vom Sternenhimmel, Erlenbach-Zurich, E. Rentsch,1940, Brunner William, Contributions to the photometry of night sky, Zurich,1935. Brunner, William, Anzeige des Todes von Alfred Wolfer, Astronomische Nachrichten, Brunner, William, Helligkeitsmessungen von Nova 60.1927 Aquilae, Astronomische Nachrichten, volume 230,1927. Brunner, William, Dreht sich die erde, leipzig und Berlin, B. G. Teubner,1915

3.
Johann Baptist Cysat
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Johann Baptist Cysat was a Swiss Jesuit mathematician and astronomer, after whom the lunar crater Cysatus is named. In 1604, Cysat joined the Jesuits and became a student in March 1611 in Ingolstadt. There he met Christoph Scheiner, whom he assisted in the observation of sunspots. In 1618, Cysat was named professor of mathematics at the University of Ingolstadt, succeeding Scheiner in this position, Cysat became one of the first to make use of the newly developed telescope. Cysats most important work was on comets, and he observed the comet of 1618 and he published a monograph on the comet called Mathemata astronomica de loco, motu, magnitudine et causis cometae qui sub finem anni 1618 et initium anni 1619 in coelo fulsit. According to Cysat’s opinion, comets circled around the sun, and he demonstrated at the time that the orbit of the comet was parabolic. Cysat’s observations on the comet are characterized by their great detail, Cysat saw enough detail to be the first to describe cometary nuclei, and was able to track the progression of the nucleus from a solid shape to one filled with starry particles. Cysat’s drawings of cometary nuclei were included on the maps of others and his observations of the comet were so detailed that in 1804, he was still considered one of its excellent observers. This work also includes Cysat’s observations on the Orion Nebula, which he compared to the nature of the comet, Cysat’s book is also remarkable due to the fact that it had been printed by a woman, Elizabeth Angermar. During the seventeenth century, regulations laid down by printing guilds sometimes allowed widows, Cysat observed the full lunar eclipse of 1620. He served as rector at the Jesuit College in Lucerne from 1624 to 1627. After a stay in Spain in 1627, where he taught at the Jesuit Colegio Imperial de Madrid, he returned to Ingolstadt in 1630 and served as rector in Innsbruck in 1637 and Eichstatt in 1646. Johannes Kepler visited Cysat in Ingolstadt, but only one letter of their correspondence, dated February 23,1621, on November 7,1631, Cysat observed the partial coverage of the sun by the planet Mercury predicted by Kepler. Cysat subsequently returned to his hometown of Lucerne, where he died on March 17,1657

4.
Leonhard Euler
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He also introduced much of the modern mathematical terminology and notation, particularly for mathematical analysis, such as the notion of a mathematical function. He is also known for his work in mechanics, fluid dynamics, optics, astronomy, Euler was one of the most eminent mathematicians of the 18th century, and is held to be one of the greatest in history. He is also considered to be the most prolific mathematician of all time. His collected works fill 60 to 80 quarto volumes, more than anybody in the field and he spent most of his adult life in Saint Petersburg, Russia, and in Berlin, then the capital of Prussia. A statement attributed to Pierre-Simon Laplace expresses Eulers influence on mathematics, Read Euler, read Euler, Leonhard Euler was born on 15 April 1707, in Basel, Switzerland to Paul III Euler, a pastor of the Reformed Church, and Marguerite née Brucker, a pastors daughter. He had two sisters, Anna Maria and Maria Magdalena, and a younger brother Johann Heinrich. Soon after the birth of Leonhard, the Eulers moved from Basel to the town of Riehen, Paul Euler was a friend of the Bernoulli family, Johann Bernoulli was then regarded as Europes foremost mathematician, and would eventually be the most important influence on young Leonhard. Eulers formal education started in Basel, where he was sent to live with his maternal grandmother. In 1720, aged thirteen, he enrolled at the University of Basel, during that time, he was receiving Saturday afternoon lessons from Johann Bernoulli, who quickly discovered his new pupils incredible talent for mathematics. In 1726, Euler completed a dissertation on the propagation of sound with the title De Sono, at that time, he was unsuccessfully attempting to obtain a position at the University of Basel. In 1727, he first entered the Paris Academy Prize Problem competition, Pierre Bouguer, who became known as the father of naval architecture, won and Euler took second place. Euler later won this annual prize twelve times, around this time Johann Bernoullis two sons, Daniel and Nicolaus, were working at the Imperial Russian Academy of Sciences in Saint Petersburg. In November 1726 Euler eagerly accepted the offer, but delayed making the trip to Saint Petersburg while he applied for a physics professorship at the University of Basel. Euler arrived in Saint Petersburg on 17 May 1727 and he was promoted from his junior post in the medical department of the academy to a position in the mathematics department. He lodged with Daniel Bernoulli with whom he worked in close collaboration. Euler mastered Russian and settled life in Saint Petersburg. He also took on a job as a medic in the Russian Navy. The Academy at Saint Petersburg, established by Peter the Great, was intended to improve education in Russia, as a result, it was made especially attractive to foreign scholars like Euler