Edmond Halley(1656 — 1742)
Edmond Halley
royaume de Grande-Bretagne, royaume d'Angleterre
9 min read
An English astronomer and scientist of the 17th–18th century, he is famous for calculating the orbit of the comet that bears his name and predicting its return. A friend and patron of Newton, he played an essential role in the publication of the Principia Mathematica.
Frequently asked questions
Key Facts
- 1656: born in Haggerston, England
- 1676: catalogue of 341 stars of the southern hemisphere, observed from the island of Saint Helena
- 1687: funds and oversees the publication of Newton's Principia Mathematica
- 1705: predicts the return of the comet of 1682, which will bear his name (Halley's Comet, period ~76 years)
- 1742: dies in Greenwich; the comet returns in 1758, confirming his prediction
Works & Achievements
The first accurate catalogue of stars in the southern hemisphere, containing 341 stellar positions measured at Saint Helena. This pioneering work earned him the nickname 'the Tycho Brahe of the South' and immediate election to the Royal Society.
Halley persuaded Newton to publish his masterwork, oversaw its editing and layout, and funded the printing out of his own pocket. Without him, this scientific revolution might have remained buried in Newton's desk drawers.
The world's first global map of magnetic declinations, the fruit of his Atlantic expeditions. It allowed 18th-century navigators to correct their compasses and determine their position at sea with unprecedented accuracy.
A comparative study of twenty-four historical comets in which Halley demonstrated that the comets of 1531, 1607, and 1682 were one and the same comet following a periodic orbit, and predicted its return in 1758 — confirmed 16 years after his death.
A memoir in which Halley proposed using the transit of Venus across the Sun to calculate the Earth-Sun distance by parallax. His instructions guided astronomers during the transits of 1761 and 1769, ushering in an era of precise cosmic measurement.
Tables of the Moon's position compiled by Halley during his years at Greenwich, published after his death. They served as an essential reference for astronomical navigation throughout the 18th century.
Anecdotes
In 1687, Isaac Newton was hesitant to publish his work due to lack of funds and fear of controversy. Edmond Halley made the remarkable decision to personally finance, out of his own fortune, the printing of the Principia Mathematica. Without this act, one of the most important works in the history of science might never have seen the light of day.
In 1705, Halley published a study comparing the orbits of several comets observed between 1337 and 1698. He noticed that the comets of 1531, 1607, and 1682 had nearly identical trajectories and concluded that they were the same celestial body returning approximately every 75–76 years. He predicted its return for 1758 — sixteen years after his own death — and this prediction proved correct, brilliantly confirming Newton's law of universal gravitation.
At just 20 years old, Halley left Oxford before completing his degree to sail to the island of Saint Helena in the South Atlantic. He spent nearly two years there observing the southern sky, cataloguing 341 stars invisible from Europe. Upon his return in 1678, he was nicknamed the “Tycho Brahe of the South” and elected to the Royal Society at just 22 years old.
Halley invented one of the first practical diving apparatuses: a reinforced wooden diving bell equipped with barrels of compressed air sent down from the surface. In 1691, he personally descended to a depth of 18 meters in the Thames and remained there for over an hour. This invention paved the way for the first underwater explorations and shipwreck salvage operations.
Halley was one of the first scientists to attempt to measure the Earth-Sun distance. He proposed observing the transit of Venus across the Sun from different points around the globe to calculate this distance by parallax. Knowing he would not live long enough to see the next transit (scheduled for 1761), he wrote detailed instructions for future astronomers — a kind of posthumous scientific message.
Primary Sources
By comparing the orbital elements of twenty-four comets observed between 1337 and 1698, I have reached the conclusion that the comets of 1531, 1607, and 1682 are one and the same celestial body returning periodically. I therefore predict with confidence its return around the year 1758.
This catalogue presents the positions of three hundred and forty-one stars of the southern hemisphere, observed at the island of Saint Helena between 1676 and 1678 by means of a telescopic sextant of five and a half feet radius.
The variations in atmospheric pressure observed at different altitudes appear to follow a regular law which, if better understood, would allow the altitude of a location to be deduced by simply reading the barometer.
Here at last, benevolent reader, is the fruit of the most profound meditations of the celebrated Newton. May the mortals who read these pages recognise the greatness of the human mind and the glory of English genius.
This general chart of magnetic declination, based on my own observations at sea during my voyages from 1698 to 1700, is intended to guide navigators in correcting their instruments and determining their longitude.
Key Places
A district in east London where Edmond Halley was born in 1656, into a prosperous family. This city, in the midst of an intellectual flourishing marked by the founding of the Royal Society in 1660, shaped his scientific vocation.
An isolated volcanic island in the middle of the Atlantic where Halley stayed from 1676 to 1678 to observe the southern sky. It was there that he compiled his catalogue of 341 stars and earned his international reputation as an astronomer.
An institution founded in 1675 of which Halley became the second director (Astronomer Royal) in 1720. He spent the last twenty years of his life there refining the lunar tables essential to navigation.
Halley studied at Queen's College from 1673 before leaving for Saint Helena without completing his degree. He returned as the full professor of the Savilian Chair of Geometry from 1703 to 1742.
Halley commanded the vessel *Paramour* on two scientific expeditions across the Atlantic, collecting magnetic data from the Arctic to the Antarctic. These voyages resulted in the first world map of magnetic declination.
