Richard Jack (mathematician) facts for kids
Richard Jack (died 1759) was a smart Scottish man who worked with mathematics, astronomy, and engineering in the mid-18th century. He helped create special lenses that made telescopes better. His work on shapes called conic sections was even used in the very first Encyclopaedia Britannica.
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About Richard Jack's Life
Richard Jack was born in Scotland, part of Great Britain, likely between 1710 and 1715. He married Elizabeth Brown on March 14, 1737. Around this time, he was teaching mathematics in Newcastle-upon-Tyne. They later had a son, also named Richard.
Jack gave talks about math in Edinburgh, probably from 1739 to 1743. He even put advertisements in a newspaper called the Caledonian Mercury. He was supported by Hugh Hume-Campbell, a powerful earl, who he helped observe sunspots.
Jack and the Jacobite Uprising
During the Jacobite uprising in 1745, Richard Jack stayed loyal to King George II. He volunteered to help place cannons in Edinburgh. He worked as a fortifications engineer under Professor Colin MacLaurin.
When Charles Edward Stuart's forces entered Edinburgh without a fight on September 17, Jack left with most of the other loyal soldiers. He then went to spy on the Stuart forces. On September 19, he counted their men camped on Arthur's Seat.
Jack later said he helped plan where to put artillery and even fired two cannons himself. He claimed he hit Stuart men hiding in a church at Tranent. However, other people said Jack only claimed to know about ballistics (how guns work). They said he wasn't involved in the army's plans. He did scout some areas and helped direct fire, but he was not good at using the cannons himself.
The next day, September 21, was the Battle of Prestonpans. Jack said he and four sailors worked two cannons. But other witnesses said the sailors ran away before the battle. They also said Jack was sent away because he wasn't useful and wasn't seen fighting.
A year later, on September 24, 1746, Jack was the only person to speak under oath at a court martial (a military trial). This trial was for Lieutenant General John Cope, the commander. Jack said he saw three officers, possibly including Cope, run away from the battle. But because Jack had made exaggerated claims before, and no one else supported his story, the court didn't believe him. General Cope was found innocent, but he never held a high position again.
New Inventions and Lectures
On May 25, 1750, Jack received a patent (a special right for an invention). This patent was for a "quadrant" (a tool to measure the height of the sun or moon) and a "refracting telescope with four spherical lenses." He got this patent with George Adams, a successful instrument maker in London.
They claimed their telescope could magnify things 30 times and removed blurry colors. Other instrument makers argued against these claims. But in early 1752, tests seemed to prove Jack and Adams right. They made a good profit from their design.
No examples of these devices exist today. However, records suggest that the Board of Admiralty or Board of Ordnance (groups in charge of the navy and military supplies) liked the telescope's high magnification. This was very important for long-range shooting.
Jack also gave talks about math in London in 1751 and 1754. He also lectured on experimental philosophy (science experiments), fortification (building defenses), and gunnery (using cannons).
Jack's Final Years
Richard Jack died in 1759. An advertisement for his probate auction said he had been an "assistant engineer" in a recent military trip. This trip was against Guadeloupe, a French colony captured by British forces during the Seven Years' War. Among his belongings were an air pump, a microscope, telescopes, and other scientific tools.
Richard Jack's Writings
Richard Jack wrote three main books:
- A book about conic sections (shapes like circles, ellipses, parabolas).
- A book about trigonometry (a branch of math dealing with triangles).
- A book about astronomy.
Jack also started a fourth book called The Doctrine of Proportion Geometrically Demonstrated. He wrote most of it before 1745. But he lost the manuscript when Stuart forces searched his home during their time in Edinburgh.
Jack's work on conic sections was a very important source for the first edition of the Encyclopaedia Britannica in 1771. However, his work trying to prove the existence of God using geometry was not well-regarded. People like MacFarlane called it "one of the most absurd" attempts to use mathematical reasoning for religious questions. Another writer, George Simpson, said Jack's ideas showed how the human mind can sometimes lean towards absurdity.
