In honor of National Surveyors Week (March 19-25) in the US and Global Surveyors Day (March 21), here's five of the most influential surveyors throughout history, reaching back from 2023 back to the second century for the earliest industry pioneers.
Claudius Ptolemy (100—170) was an Egyptian astronomer, mathematician, and geographer of Greek descent who flourished in Alexandria during the 2nd century CE. Ptolemy’s most important geographical innovation was to record longitudes and latitudes in degrees for roughly 8,000 locations on his world map, making it possible to make an exact duplicate of his map. Ptolemy also devised two ways of drawing a grid of lines on a flat map to represent the circles of latitude and longitude on the globe. His grid gives a visual impression of Earth’s spherical surface and also, to a limited extent, preserves the proportionality of distances. The more sophisticated of these map projections, using circular arcs to represent both parallels and meridians, anticipated later area-preserving projections.
Map of China created by Pei Xiu. Image courtesy of Wikimedia Commons.
Pei Xiu (224–271), known as the father of cartography, was a Chinese cartographer, geographer, politician, and writer of the state of Cao Wei during the late Three Kingdoms period and Jin dynasty of China. He was the first to mention a plotted geometrical grid reference and graduated scale displayed on the surface of maps to gain greater accuracy in the estimated distance between different locations, also identifying the six rules of cartography (Plotting Scale, Azimuth, Alignment Station, Contour, Angle-off set and Polyline). Historian Howard Nelson asserts that there is ample written evidence that Pei Xiu derived the idea of the grid reference from the map of Zhang Heng (78–139 CE), a polymath inventor and statesman of the Eastern Han period.
Benjamin Banneker (1731–1806) was a free African American almanac author, surveyor, naturalist, and farmer. Born in Baltimore County, Maryland, to a free African American woman and a former slave, Banneker had little formal education and was largely self-taught. He is known for being part of a group led by Major Andrew Ellicott that surveyed the original borders of the District of Columbia, the federal capital district of the United States. Banneker's knowledge of astronomy helped him author a commercially successful series of almanacs. He corresponded with Thomas Jefferson on the topics of slavery and racial equality, Jefferson having earlier drafted the United States Declaration of Independence.
Courtesy: Winnipeg Free Press
David Thompson (1770 – 1857) was a British-Canadian fur trader, surveyor, and cartographer, known to some native peoples as Koo-Koo-Sint or "the Stargazer." Over Thompson's career, he traveled some 90,000 kilometers (56,000 mi) across North America, mapping 4.9 million square kilometers (1.9 million square miles) of North America along the way. For this historic feat, Thompson has been described as the "greatest land geographer who ever lived."
Irene Turberville Martin (Barclay) (1894–1989) and Evelyn Perry were the first and second women to obtain Chartered Surveyor licensures in England in 1922 and 1923, respectively. Barclay became a Fellow in 1931 and Perry in 1937. They formed a partnership, Barclay and Perry, which they ran until 1940. Barclay continued to practice until 1972, marking 50 years in the profession. She was an active social reformer, focusing on improving housing conditions in the St. Pancras slums in London between the First and Second World Wars. She received the Order of the British Empire for her volunteer work and is commemorated in the Somers Town Mural in Camden.