John Robertson (mathematician) facts for kids

John Robertson (born 1712, died 1776) was an English mathematician. He was also a member, clerk, and librarian of the Royal Society. His famous book, The Elements of Navigation, became a very important textbook for sailors.

John Robertson's Life Story

John Robertson first started learning a trade. But he soon became a teacher of mathematics. In 1741, he was chosen to be a member of the Royal Society. This is a famous group for scientists. In 1747, he became the master of the Royal Mathematical School at Christ's Hospital. He worked there as an assistant to James Hodgson.

In 1755, Robertson became the first master of the Royal Naval Academy, Portsmouth. This was a school for training naval officers. He lost this job in 1766. After that, he moved back to London. On January 7, 1768, he was hired by the Royal Society. He became their clerk and librarian. He kept these jobs until he passed away on December 11, 1776.

His Books and Scientific Work

Robertson published his first book in 1739. It was called Completed Treatise on Mensuration. This book was about measuring things. After this, he became a Fellow of the Royal Society in 1741. In 1747, he released the first version of A Treatise of Such Mathematical Instruments as are Usually put into a Portable Case. This book was about different math tools. It was printed four more times over the next 30 years. It became a textbook at the Royal Mathematical School and the Royal Navy Academy.

The teachers at the Royal Mathematical School wrote excellent math books. Following this tradition, Robertson wrote a two-volume book. It was titled The Elements of Navigation. This book taught both the ideas and the practical skills for navigation. It included tables and ways to find a ship's location at sea. It also had a part about building defenses for ships. The first edition came out in 1754. The Elements of Navigation was printed seven times in 50 years. The first part of the book covered many topics. These included logarithms, Euclidean geometry, and how to use maps and stars. It also taught different ways of sailing and how to estimate distances.

Students at the Royal Mathematical School were trained for the Royal Navy. The math standards there were very high. The Royal Navy Academy followed a similar learning plan. Robertson became a math teacher there in 1755. His book, The Elements of Navigation, was used daily by students. This was between 1755 and 1775. By 1776, the book was considered a classic. It was one of the best English navigation guides of its time. After Robertson moved to the Royal Navy Academy, his book shaped their math and navigation lessons. In 1773, these two schools were called the best math schools in England. When Robertson died in 1777, William Wales updated the book. A new edition came out in 1780. It was credited to both Robertson and Wales.

In 1750, Robertson published a translation of a book on astronomy. He also wrote nine papers for a science journal called Philosophical Transactions. These papers were published between 1750 and 1772. They covered topics like math, water movement, and how much living men weigh.

After losing his job at the Royal Naval Academy in 1766, Robertson became a clerk and librarian. He worked for the Royal Society until he died. He kept doing scientific work. He was the first to show a special way to draw maps. This method kept the shapes accurate. In 1775, he made the first slide rule with a movable part. Robertson also checked and set up John Harrison's very important clock, the chronometer H4. This was before its first sea test in November 1761. People respected him greatly. He was asked for help to survey the Mason–Dixon line. This line marked the border between Maryland and Pennsylvania in North America.

John Robertson's Family

John Robertson was married. When he died, his wife was left with eight children. She worked for the Royal Society as a housekeeper. Their oldest son also worked as a librarian for the Royal Society.