Alicia Bailey

Ellsworth High School

Calculus Class

December 2001

Jean Picard was born on July 21, 1620 in La Fleche, France. His father was also Jean Picard. His father was a bookseller in La Fleche. There is little known of Picard's youth and the finical status during his youth. There is also little known on Picard's mother and father.

He studied at the Jesuit College in La Fleche. In 1650, Picard earned his M.A. (B.A.) from the college in Paris. Little is known of what Picard did between his time in college at La Fleche and his time at the college in Paris. Picard spent a lot of time studying celestial objects such as the Sun, Moon, and planets. In 1655 Picard became a professor of astronomy at the College de France in Paris. Picard spent a lot of time working on astrology, but he did spend some time working in mathematics.

Picard mostly dealt with measurements in the mathematical field. He increased the accuracy of measurements of the Earth and measured the arc length of the meridian. By studying the measurements of the earth and other planets he was able to increase the accuracy of the equations that were already used in that day of age.

In 1666 Picard became a member of the Academie Royale des Sciences. This was a group of some of the best scientists and mathematicians in the world gathered together to produce a map of the entire world. The main problem with the map of the world was the "longitude problem." These men could not figure out exactly how to draw the longitudinal lines on the map. The worked with equations and measurements to solve this problem. They had figured out the longitude lines on land, but they could not figure out what they were on sea. Picard's main achievement in this project was his expedition. On his expedition he realized that his pendulum clock was off. We now know that that was because he was closer t the equator.

Picard was a member of the Catholic Church. He was ordained a priest in 1650. He also held at least four benefices. Picard was not as priest for a long time. He spent much of his time with astronomy, instrumentation, cartography, physics, optics, and hydraulics.

With Auzout, Picard perfected the movable-wire micrometer. He was the one that incorporated that astronomical telescope into surveying instruments such as the quadrant and the sector. He also developed a new leveling instrument that remained the standard one used in leveling for a long time. He was also the primary factor in planning and implementing the water supply for the fountains at Versailles.

While most of his works were scientific, Picard made many mathematical contributions. His works in instrumentation and finding diameter are very important to the math world. Picard died in Paris on October 12, 1682. He lived for 62 years. That is not very long considering how much he did in his lifetime.