Thomas Hubbard Sumner
Encyclopedia
Thomas Hubbard Sumner was a sea captain during the 19th century. He is best known for developing the celestial navigation
method known as the Sumner Line or line of position.
At the age of 19, shortly after graduating, he married and ran off to New York with a woman with whom he had become entangled but the marriage was short-lived and they were divorced three years later. He then enrolled as a common sailor on a ship engaged in the China trade and within eight years he had risen to the rank of captain and was master of his own ship. On March 10, 1834 he married Selina Christiana Malcolm, of Connecticut and between 1835 and 1848 together they had six children, two of whom died in their infancy.
On November 25, 1837, Sumner sailed from Charleston, South Carolina, bound for Greenock, Scotland, and it was during that voyage, while entering the channel of Saint George and the Irish sea, that he discovered the principle upon which his new method of navigation was based. He took some years to perfect it and published it in the form of a short book in 1843.
Shortly after that his mind began to fail and in 1850 he was committed to the McLean Asylum
in Boston. His state gradually deteriorated and in 1865 he was committed to the Lunatic Hospital
at Taunton, Massachusetts
, where he died in 1876 at the age of 69.
Two survey ships in the United States Navy have been named for him, USS Sumner
. Also, the crater Sumner
on the Moon is named after him.
to Scotland
in 1837. On December 17, 1837, as he was nearing the coast of Wales, he was uncertain of his position after several days of cloudy weather and no sights. A momentary opening in the clouds allowed him to take a sight of the sun which he reduced with his estimated latitude
but, being uncertain about the latitude he reduced the sight again using 10' greater and 20' greater latitude and he observed that all three resulting positions were located in a straight line which also happened to pass through a navigation light near the coast. He reasoned that he must be located somewhere along that line and so he set course along that line reasoning that he should eventually sight the light which, in fact he did. He realized that a single observation of the altitude of a celestial body determines the position of a line somewhere on which the observer is located. Sumner published his findings six years later in 1843 and this method of resolving a sight for two different latitudes and drawing a "line of position" through the two positions obtained was an important development in celestial navigation. The method was instantly recognized as important and a copy of the pamphlet describing the method was supplied to every ship in the United States Navy
.
Celestial navigation
Celestial navigation, also known as astronavigation, is a position fixing technique that has evolved over several thousand years to help sailors cross oceans without having to rely on estimated calculations, or dead reckoning, to know their position...
method known as the Sumner Line or line of position.
Biography
Thomas Hubbard Sumner was born in Boston on March 20, 1807, the son of Thomas Waldron Sumner, an architect, and Elizabeth, daughter of Thomas Hubbard, of Weston Massachusetts. Sumner was one of eleven children, four of whom died young. Of the seven that survived he was the only son. He entered Harvard at age fifteen.At the age of 19, shortly after graduating, he married and ran off to New York with a woman with whom he had become entangled but the marriage was short-lived and they were divorced three years later. He then enrolled as a common sailor on a ship engaged in the China trade and within eight years he had risen to the rank of captain and was master of his own ship. On March 10, 1834 he married Selina Christiana Malcolm, of Connecticut and between 1835 and 1848 together they had six children, two of whom died in their infancy.
On November 25, 1837, Sumner sailed from Charleston, South Carolina, bound for Greenock, Scotland, and it was during that voyage, while entering the channel of Saint George and the Irish sea, that he discovered the principle upon which his new method of navigation was based. He took some years to perfect it and published it in the form of a short book in 1843.
Shortly after that his mind began to fail and in 1850 he was committed to the McLean Asylum
McLean Hospital
McLean Hospital is a psychiatric hospital in Belmont, Massachusetts.It is noted for its clinical staff expertise and ground-breaking neuroscience research...
in Boston. His state gradually deteriorated and in 1865 he was committed to the Lunatic Hospital
Taunton State Hospital
The Taunton State Hospital is a psychiatric hospital built in 1854 in Taunton, Massachusetts....
at Taunton, Massachusetts
Taunton, Massachusetts
Taunton is a city in Bristol County, Massachusetts, United States. It is the seat of Bristol County and the hub of the Greater Taunton Area. The city is located south of Boston, east of Providence, north of Fall River and west of Plymouth. The City of Taunton is situated on the Taunton River...
, where he died in 1876 at the age of 69.
Two survey ships in the United States Navy have been named for him, USS Sumner
USS Sumner
Sumner has been the name of four ships in the United States Navy. The destroyers, DD-333 and DD-692, were named after World War I Marine Corps Captain Allen Melancthon Sumner...
. Also, the crater Sumner
Sumner (crater)
Sumner is a lunar crater on the far side of the Moon, beyond the northeastern limb. It is southwest of the larger crater Szilard, and southeast of the twin walled plains Fabry and Harkhebi....
on the Moon is named after him.
Discovery
He "discovered" the (later so-called) line of position, which he named "parallel of equal altitude" on a voyage from South CarolinaSouth Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
to Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
in 1837. On December 17, 1837, as he was nearing the coast of Wales, he was uncertain of his position after several days of cloudy weather and no sights. A momentary opening in the clouds allowed him to take a sight of the sun which he reduced with his estimated latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
but, being uncertain about the latitude he reduced the sight again using 10' greater and 20' greater latitude and he observed that all three resulting positions were located in a straight line which also happened to pass through a navigation light near the coast. He reasoned that he must be located somewhere along that line and so he set course along that line reasoning that he should eventually sight the light which, in fact he did. He realized that a single observation of the altitude of a celestial body determines the position of a line somewhere on which the observer is located. Sumner published his findings six years later in 1843 and this method of resolving a sight for two different latitudes and drawing a "line of position" through the two positions obtained was an important development in celestial navigation. The method was instantly recognized as important and a copy of the pamphlet describing the method was supplied to every ship in the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
.
Further reading
- Capt. Thomas H. Sumner, A New and Accurate Method of Finding a Ship's Position at Sea, by Projection on Mercator's Chart, July 1843, Thomas Groom & Company of Boston