Third principal meridian
{{Short description|US Survey line}}
File:USBLM meridian map point of beginning.jpgs in Illinois, Indiana, and Ohio]]
The third principal meridian begins at the mouth of the Ohio River and extends north to the northern boundary of the state of Illinois, and with the base line in latitude 38° 28′ 20″{{vague|In what geodetic datum?|date=October 2022}}, governs the surveys in the state east of the third principal meridian, with the exception of those projected from the second principal meridian, and the surveys on the west, to the Illinois River. This meridian is nearly coincident with 89° 10′ 15″{{vague|In what geodetic datum?|date=October 2022}} of west longitude from Greenwich.
External links
- {{cite web
|url=http://www.pmproject.org/3pm.htm
|publisher=Principal Meridian Project
|title=The Third Principal Meridian
|accessdate=2012-09-15}}
- {{cite web
|url=http://www.clui.org/section/third-principal-meridian
|publisher=The Center for Land Use Interpretation
|title=Third Principal Meridian
|accessdate=2012-09-15}}
- {{cite web
|url=http://www.historyillinois.org/FindAMarker/MarkerDetails.aspx?MarkerID=385
|publisher=Illinois State Historical Society
|title=Historic Marker: The Third Principal Meridian
|accessdate=2016-10-28}}
Sources
- {{cite book
| last = Raymond
| first = William Galt
| title = Plane Surveying for Use in the Classroom and Field
| url = https://archive.org/details/planesurveyingf00raymgoog
| format = via Internet Archive
| date = 1914
| publisher = American Book Company
| location = New York
}}
- {{cite book
| url = http://www.dot.state.il.us/desenv/survey/chap5.pdf
| title = Survey Manual
| publisher = Illinois Department of Transportation, Bureau of Design and Environment
| location = Springfield, Illinois
| date = 2003-02-28
| chapter = Chapter Five: Land Surveying
| pages = 5
| accessdate = 2008-10-30
| archive-date = 2011-05-25
| archive-url = https://web.archive.org/web/20110525044629/http://www.dot.state.il.us/desenv/survey/chap5.pdf
| url-status = dead
}}
{{Principal meridians of the United States}}
{{coord|38|28|26|N|89|08|40|W|format=dms|display=title|type:landmark_region:US-IL}}