Charles Mason
Encyclopedia
Charles Mason was an English
astronomer
who made significant contributions to 18th-century science and American history, particularly through his involvement with the survey of the Mason-Dixon line
, which came to mark the division between the northern and southern United States
(1764–1768).
. He served as assistant astronomer from 1756 to 1760 under the Reverend James Bradley, Astronomer Royal.
While employed at the Greenwich Observatory, Mason became familiar with Professor Tobias Mayer’s
Tables of the Moon. The Lunar Tables were designed to solve the problem of determining longitude at sea
, a challenge that frustrated scientists and navigators for decades. Mason worked throughout his life to perfect the Lunar Tables as a method of improving navigation at sea. In 1787, Mason was awarded £750 by the Board of Longitude
for his work on perfecting the Tables.
to observe the Transit of Venus
as part of an international effort to record data that would enable scientists to determine the distance from the earth to the sun. Mason was joined by Jeremiah Dixon
, a surveyor and amateur astronomer from Cockfield in the County of Durham. Owing to an attack by a French man-of-war, they did not reach their destination in time for the transit and were forced to record their observations from the Cape of Good Hope
.
and Maryland
. Colonial surveyors had been unable to accurately establish the boundary due to their poor training and inadequate scientific instruments. Mason and Dixon, accompanied by a large party of assistants, established three important boundaries: (1) the south boundary line of Pennsylvania separating it from Maryland and Virginia
; (2) the west boundary of the three lower counties of Pennsylvania (now Delaware
) separating it from Maryland; and (3) the south boundary of the three lower counties. The pair also conducted a number of experiments for the Royal Society such as measuring a degree of longitude. Mason’s journal provides the most complete record of the survey and its progress. The journal includes his astronomical observations and personal notes about the American frontier environment and his experiences in colonial America.
Mason and Dixon failed to measure the entire length of the south boundary of Pennsylvania as determined by its charter. In the summer of 1767, the surveying party crossed the Monongahela River
and the Great Catawba War Path
, violating a treaty limiting the westward expansion of English settlements. Not wishing to risk inciting native hostilities, Mason and Dixon were forced to return east after making their final observations at the crest of Brown's Hill.
, working under Nevil Maskelyne
, Astronomer Royal.
On September 27, 1786, Mason wrote to Benjamin Franklin
that he had returned to Philadelphia with his wife, seven sons, and one daughter. Mason was very ill and confined to his bed. Mason also shared with Franklin the design for an astronomical project. Mason provided no explanation for his return to America, and nothing more is known of Mason's proposed project.
Mason died on October 26, 1786, in Philadelphia.
on the Moon
is named after him.
Mason is one of the titular characters of Thomas Pynchon
's 1997 novel Mason & Dixon
.
The song Sailing to Philadelphia
from Mark Knopfler
's album of the same name, also has strong references to Mason and Dixon, and was inspired by Pynchon's book.
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
who made significant contributions to 18th-century science and American history, particularly through his involvement with the survey of the Mason-Dixon line
Mason-Dixon line
The Mason–Dixon Line was surveyed between 1763 and 1767 by Charles Mason and Jeremiah Dixon in the resolution of a border dispute between British colonies in Colonial America. It forms a demarcation line among four U.S. states, forming part of the borders of Pennsylvania, Maryland, Delaware, and...
, which came to mark the division between the northern and southern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
(1764–1768).
Early career
Mason's early career was spent at the Royal Greenwich Observatory near LondonLondon
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
. He served as assistant astronomer from 1756 to 1760 under the Reverend James Bradley, Astronomer Royal.
While employed at the Greenwich Observatory, Mason became familiar with Professor Tobias Mayer’s
Tobias Mayer
Tobias Mayer was a German astronomer famous for his studies of the Moon.He was born at Marbach, in Württemberg, and brought up at Esslingen in poor circumstances. A self-taught mathematician, he had already published two original geometrical works when, in 1746, he entered J.B. Homann's...
Tables of the Moon. The Lunar Tables were designed to solve the problem of determining longitude at sea
History of longitude
The history of longitude is a record of the effort, by navigators and scientists over several centuries, to discover a means of determining longitude....
, a challenge that frustrated scientists and navigators for decades. Mason worked throughout his life to perfect the Lunar Tables as a method of improving navigation at sea. In 1787, Mason was awarded £750 by the Board of Longitude
Board of Longitude
The Board of Longitude was the popular name for the Commissioners for the Discovery of the Longitude at Sea. It was a British Government body formed in 1714 to administer a scheme of prizes intended to encourage innovators to solve the problem of finding longitude at sea.-Origins:Navigators and...
for his work on perfecting the Tables.
1761 transit of Venus
In 1761, Mason was assigned to travel to the island of SumatraSumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
to observe the Transit of Venus
Transit of Venus
A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and Earth, becoming visible against the solar disk. During a transit, Venus can be seen from Earth as a small black disk moving across the face of the Sun...
as part of an international effort to record data that would enable scientists to determine the distance from the earth to the sun. Mason was joined by Jeremiah Dixon
Jeremiah Dixon
Jeremiah Dixon was an English surveyor and astronomer who is perhaps best known for his work with Charles Mason, from 1763 to 1767, in determining what was later called the Mason-Dixon line....
, a surveyor and amateur astronomer from Cockfield in the County of Durham. Owing to an attack by a French man-of-war, they did not reach their destination in time for the transit and were forced to record their observations from the Cape of Good Hope
Cape of Good Hope
The Cape of Good Hope is a rocky headland on the Atlantic coast of the Cape Peninsula, South Africa.There is a misconception that the Cape of Good Hope is the southern tip of Africa, because it was once believed to be the dividing point between the Atlantic and Indian Oceans. In fact, the...
.
The Mason–Dixon line survey
From November 1763 to 1768, Mason and Jeremiah Dixon established the boundary line between the American provinces of PennsylvaniaPennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
and Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...
. Colonial surveyors had been unable to accurately establish the boundary due to their poor training and inadequate scientific instruments. Mason and Dixon, accompanied by a large party of assistants, established three important boundaries: (1) the south boundary line of Pennsylvania separating it from Maryland and Virginia
West Virginia
West Virginia is a state in the Appalachian and Southeastern regions of the United States, bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, Pennsylvania to the northeast and Maryland to the east...
; (2) the west boundary of the three lower counties of Pennsylvania (now Delaware
Delaware
Delaware is a U.S. state located on the Atlantic Coast in the Mid-Atlantic region of the United States. It is bordered to the south and west by Maryland, and to the north by Pennsylvania...
) separating it from Maryland; and (3) the south boundary of the three lower counties. The pair also conducted a number of experiments for the Royal Society such as measuring a degree of longitude. Mason’s journal provides the most complete record of the survey and its progress. The journal includes his astronomical observations and personal notes about the American frontier environment and his experiences in colonial America.
Mason and Dixon failed to measure the entire length of the south boundary of Pennsylvania as determined by its charter. In the summer of 1767, the surveying party crossed the Monongahela River
Monongahela River
The Monongahela River is a river on the Allegheny Plateau in north-central West Virginia and southwestern Pennsylvania in the United States...
and the Great Catawba War Path
Great Indian Warpath
The Great Indian Warpath — also known as the Great Indian War and Trading Path, or the Seneca Trail — was that part of the network of trails in eastern North America developed and used by Native Americans which ran through the Great Appalachian Valley...
, violating a treaty limiting the westward expansion of English settlements. Not wishing to risk inciting native hostilities, Mason and Dixon were forced to return east after making their final observations at the crest of Brown's Hill.
Career after the Mason-Dixon line survey
After completing the boundary survey in America, Mason returned to Greenwich where he continued work on Mayer's Lunar Tables. He also contributed to the Nautical AlmanacHM Nautical Almanac Office
Her Majesty's Nautical Almanac Office , now part of the United Kingdom Hydrographic Office, was established in 1832 on the site of the Royal Greenwich Observatory , where the Nautical Almanac had been published since 1767...
, working under Nevil Maskelyne
Nevil Maskelyne
The Reverend Dr Nevil Maskelyne FRS was the fifth English Astronomer Royal. He held the office from 1765 to 1811.-Biography:...
, Astronomer Royal.
On September 27, 1786, Mason wrote to Benjamin Franklin
Benjamin Franklin
Dr. Benjamin Franklin was one of the Founding Fathers of the United States. A noted polymath, Franklin was a leading author, printer, political theorist, politician, postmaster, scientist, musician, inventor, satirist, civic activist, statesman, and diplomat...
that he had returned to Philadelphia with his wife, seven sons, and one daughter. Mason was very ill and confined to his bed. Mason also shared with Franklin the design for an astronomical project. Mason provided no explanation for his return to America, and nothing more is known of Mason's proposed project.
Mason died on October 26, 1786, in Philadelphia.
Posthumous recognition
The crater MasonMason (crater)
Mason is the remains of a lunar crater that lies in the northeastern part of the Moon. It is nearly attached to the eastern rim of the flooded crater Plana, and southeast of Bürg. Along the northern rim of Mason is the southern edge of the Lacus Mortis, a small lunar mare...
on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
is named after him.
Mason is one of the titular characters of Thomas Pynchon
Thomas Pynchon
Thomas Ruggles Pynchon, Jr. is an American novelist. For his most praised novel, Gravity's Rainbow, Pynchon received the National Book Award, and is regularly cited as a contender for the Nobel Prize in Literature...
's 1997 novel Mason & Dixon
Mason & Dixon
Mason & Dixon is a postmodernist novel by American author Thomas Pynchon published in 1997. It centers on the collaboration of the historical Charles Mason and Jeremiah Dixon in their astronomical and surveying exploits in Cape Colony, Saint Helena, Great Britain and along the Mason-Dixon line in...
.
The song Sailing to Philadelphia
Sailing to Philadelphia
Sailing to Philadelphia is the second solo album by Mark Knopfler, released on 26 September 2000. The title track is drawn from Thomas Pynchon's novel about Charles Mason and Jeremiah Dixon, the two English surveyors who established the border between Pennsylvania and Maryland, Delaware and...
from Mark Knopfler
Mark Knopfler
Mark Freuder Knopfler, OBE is a Scottish-born British guitarist, singer, songwriter, record producer and film score composer. He is best known as the lead guitarist, vocalist, and songwriter for the British rock band Dire Straits, which he co-founded in 1977...
's album of the same name, also has strong references to Mason and Dixon, and was inspired by Pynchon's book.