William Herschel's 20-foot telescope set up by John Herschel in South Africa. The drawing is by John Herschel. [Image credit: Linda Hall Library]

William Herschel was the first person in history to discover a new planet. With the help of his sister Caroline he made a catalog of the nebulae of the northern hemisphere. Nebulae were distant fuzzy objects that included clouds of gas and dust, galaxies, and star clusters.

William Herschel married Mary Pitt, and their son John was born in Slough, England on March 7, 1792. Life can be difficult for the son of a famous father. However John was an intelligent and creative child who had a loving and supportive family. He grew into a thoughtful, generous adult who was also one of the greatest English scientists of the 19th century.

Education
John was sent to Eton, a famous private school. In spite of its good reputation, John's mother decided that Eton was too rough, and took him away. The rest of his education was at a local school and at home with tutors.

When John was 17 he went to Cambridge University, one of the world's oldest and most respected universities. He was an excellent mathematician. While he was still at the university, Herschel wrote a mathematical paper and sent it to the Royal Society. The Royal Society of Great Britain is an important scientific society. They published Herschel's paper and invited him to join. At 21, he was one of the youngest members ever.

From law to astronomy
Oddly, considering that Herschel's main interests were mathematics and science, his first job after graduation was in the legal profession. However this didn't suit him, and he returned to Cambridge as a math tutor.

Herschel's friend John South tried to get him interested in astronomy. But what finally convinced John was his father's request. William Herschel had married late in life, so with John in his twenties, William was well into his seventies. His health was poor and he no longer did much observing. Yet he still loved astronomy, and worried about his unfinished work.

The Herschels rebuilt the 20-foot telescope that William had used for the nebula survey. And in 1820 John helped found the Royal Astronomical Society. His father was its first president. When he died two years later, he had John's promise to complete the catalog of nebulae by observing the southern hemisphere skies.

Marriage, family and South Africa
In 1829 John Herschel married Margaret Stewart and they had a long and happy marriage. Margaret was a keen botanist, and like John, a talented musician and artist. Four years later, John, Margaret, three small children, and several telescopes sailed to Cape Town, South Africa. They spent five years there.

John studied the southern skies, making much use of the 20-foot telescope, as shown above. After they left Cape Town, a monument was built where the telescope once stood. Today there is a school there. Since Herschel helped to lay the foundation for public education in South Africa, this is very fitting.

When the Herschel family returned to England there were six children. John and Margaret had twelve children altogether, and John was a devoted father.

Knighthood, baronetcy and work
The Herschels were well known to Britain's royal family. King George III had made William Herschel the King's Astronomer. John's aunt Caroline socialized with the king's daughters. The nephews of William and Caroline were in the royal court's orchestra. George III's son King William IV had granted the royal charter to the Royal Astronomical Society, and knighted John Herschel. He was then called Sir John Herschel in recognition of this honor.

While the Herschels were in Africa, King William died, and his niece Victoria became queen. The young queen decided to further recognize John Herschel's achievements by making him a baronet, which is a hereditary title of nobility.

Sir John published over 150 scientific papers, including work on mathematics, chemistry and meteorology (weather), as well as astronomy. His book about the philosophy and practice of science was very widely read. Some of the chemistry papers were about photography. Herschel was a pioneer of photography. He invented the cyanotype process. You've probably seen old black and white photos, but cyanotype produces blue and white pictures. People called them blueprints, and for a long time architects and builders used them to make copies of large building plans.

Farewell
Britain had much respect and affection for this great man. He died on May 11, 1872, and at his funeral the presidents of scientific societies carried the coffin. Sir John Frederick William Herschel, 1st Baronet was laid to rest in Westminster Abbey not far from Sir Isaac Newton.