Edmond Halley
Edmond Halley was born in Haggerston, Middlesex, during the year 1656. His father Edmond Halley Sr. worked as a wealthy soap-maker in London and came from a Derbyshire family. The young boy showed an early fascination with mathematics that set him apart from his peers. He attended St Paul's School where he developed his initial interest in astronomy. In 1671, the school elected him captain of the student body. The following year tragedy struck when his mother Anne died. She was probably named Robinson before marriage.
In July 1673, Halley began studying at The Queen's College, Oxford University. He took a long telescope with him to the university campus. His father apparently paid for this expensive piece of equipment. While still an undergraduate student, Halley published papers on the Solar System and sunspots. In March 1675, he wrote to John Flamsteed, England's first Astronomer Royal. Halley told Flamsteed that leading published tables on Jupiter and Saturn positions were erroneous. He also noted errors in some star positions recorded by Tycho Brahe.
King Charles II supported Halley's plan to observe the southern sky. Halley chose the south Atlantic island of Saint Helena west of Africa. He sailed to the island in late 1676 and set up an observatory there. The structure housed a large sextant with telescopic sights. Over more than one year, Halley made observations from this remote location. He produced the first telescopic catalogue of the southern celestial hemisphere. This work included descriptions of 341 stars.
During his time on Saint Helena, Halley observed a transit of Mercury across the Sun. Focusing on this specific observation, he realized that observing solar parallax could determine distances between Earth, Venus, and the Sun. He understood that using the transit of Venus would be even more ideal. That event would not occur within his lifetime however. Halley returned to England in May 1678 with his data. Oxford University refused to let him return because he had violated residency requirements. King Charles II signed a letter requesting Halley receive his Master of Arts degree unconditionally. The college granted the degree on the 3rd of December 1678. Just days before, Halley became a fellow of the Royal Society at age 22.
In September 1682, Halley carried out observations of what became known as Halley's Comet. His name became associated with it due to his work on its orbit. In early 1686, Halley was elected secretary of the Royal Society. This role required him to manage correspondence and edit Philosophical Transactions. He published the second part of results from his expedition to Saint Helena in 1686. The paper included charts on trade winds and monsoons.
Halley used Newton's law of universal gravitation to compute the periodicity of the comet. He published these findings in his 1705 Synopsis of the Astronomy of Comets. He stated that comet sightings from 1456, 1531, 1607, and 1682 were actually the same object. He predicted it would return in 1758. Halley did not live to witness this return. When the comet appeared again in 1758, it became generally known as Halley's Comet. Earlier calculations for Kirch's Comet indicated a periodicity of 575 years. Modern science now knows that orbital period is approximately 10,000 years.
In 1698, King William III gave Halley command of the Paramour ship. It was described as pink in color. Halley sailed on what was the first purely scientific voyage by an English naval vessel. Problems of insubordination arose over questions of his competence to command. He returned the ship to England to proceed against officers in July 1699. The court issued a mild rebuke for his men but left Halley dissatisfied.
Halley received a temporary commission as captain in the Royal Navy. He recommissioned the Paramour on the 24th of August 1699 and sailed again in September 1699. This second Atlantic voyage lasted until the 6th of September 1700. It extended from 52 degrees north to 52 degrees south latitude. The results were published as General Chart of the Variation of the Compass in 1701. This chart featured isogonic lines showing equal magnetic declination across the Atlantic Ocean. These lines inspired later ideas such as isotherms used by Alexander von Humboldt. In 1701, Halley made a third final voyage on the Paramour to study tides of the English Channel.
In 1691, Halley built a diving bell device. The atmosphere inside was replenished by weighted barrels of air sent down from the surface. During a demonstration, Halley and five companions dived to 60 feet in the River Thames. They remained there for over an hour and half. His bell proved very heavy and little use for practical salvage work. He improved it over time extending underwater exposure to over four hours.
Halley suffered one of the earliest recorded cases of middle ear barotrauma during these dives. That same year at a Royal Society meeting he introduced a rudimentary working model of a magnetic compass. The liquid-filled housing dampened swing and wobble of the magnetized needle. In 1693 Halley published an article on life annuities featuring analysis of age-at-death data. He used Breslau statistics provided by Caspar Neumann. This work allowed the British government to sell life annuities at appropriate prices based on purchaser age. It strongly influenced development of actuarial science and demography history.
In November 1703, Halley was appointed Savilian Professor of Geometry at Oxford University. His theological enemies John Tillotson and Bishop Stillingfleet had died allowing this appointment. By 1706 Halley learned Arabic and completed translation of Books V through VII of Apollonius's Conics. Copies were found at Leiden and Bodleian Library at Oxford. He also completed new translation of first four books from original Greek started by David Gregory. These translations appeared in complete Latin edition in 1710. That same year he received honorary doctor of laws degree from Oxford.
Halley succeeded John Flamsteed in 1720 as Astronomer Royal. He held this position until his death in 1742 at age 85. In 1717-18 he discovered proper motion of fixed stars publishing findings in 1718. Arcturus and Sirius moved significantly over time. Sirius progressed 30 arc minutes southwards in 1800 years. This distance equals about diameter of the moon. Together with antiquarian William Stukeley, Halley participated in first attempt to scientifically date Stonehenge in 1716. They suggested dates including 460 BC, AD 220 and AD 920 though these proved wrong by thousands of years.
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Common questions
When and where was Edmond Halley born?
Edmond Halley was born in Haggerston, Middlesex during the year 1656. His father Edmond Halley Sr. worked as a wealthy soap-maker in London.
What did Edmond Halley observe on Saint Helena between 1676 and 1678?
Edmond Halley produced the first telescopic catalogue of the southern celestial hemisphere while stationed at Saint Helena from late 1676 to May 1678. This work included descriptions of 341 stars and observations of a transit of Mercury across the Sun.
How did Edmond Halley predict the return of his famous comet?
Edmond Halley used Newton's law of universal gravitation to compute the periodicity of the comet and stated that sightings from 1456, 1531, 1607, and 1682 were actually the same object. He predicted it would return in 1758 though he died before witnessing this event.
What scientific voyages did Edmond Halley command on the Paramour ship?
King William III gave Edmond Halley command of the Paramour ship in 1698 for what was described as the first purely scientific voyage by an English naval vessel. He sailed again in September 1699 until the 6th of September 1700 extending from 52 degrees north to 52 degrees south latitude.
When did Edmond Halley become Astronomer Royal and when did he die?
Edmond Halley succeeded John Flamsteed in 1720 as Astronomer Royal and held this position until his death in 1742 at age 85. He received honorary doctor of laws degree from Oxford University in 1710.