The Science of Surveying

by Mrs. Leone

Surveying

• The science of plotting maps of a specific locale

• Includes finding its boundaries, calculating its area, and measuring its elevation above sea level

• Uses geometry and trigonometry to measure angles and distances

Surveying Washington, D.C. • 1791-1792• Chief Surveyor: Major Andrew Ellicott,

age 37 (here at age 45)• Surveyors:

Benjamin EllicottJoseph Ellicott, age 31 (as an older man)Isaac BriggsGeorge FenwickBenjamin Banneker, age 60 (here at age 64)

Surveying Washington, D.C.

• The survey began at Jones Point, a cape located at the confluence of Hunting Creek and the Potomac River south of Alexandria, VA.

looking south

Surveying Washington, D.C.

• An area containing the full 100 square miles (260 km2) that the Residence Act had authorized on July 6, 1790

• Each side was 10 miles (16 km) long. • The axes between the corners of the square

ran north–south and east–west.

The Original Map of DC

Check it out! It was measured in “poles”!1 pole = 16.5 feet1 mile = 320 poles

Surveying Washington, D.C. • The survey team placed sandstone boundary

markers at or near every mile point along the sides of the square.

• Many of these markers still remain. • The west cornerstone is at the west corner

of Arlington County, Virginia.• The north cornerstone is south of

East-West Highway near Silver Spring, Maryland, west of 16th St.

• The east cornerstone is east of the intersection of Southern Ave and Eastern Ave.

Surveying Washington, D.C.

• What did D.C. look like before it was D.C.?

• video of Canadian surveyors doing their thing

• old fashioned surveyor’s tools