Old Hampshire Mapped

Longitude of Winchester

The longitude of Winchester has been measured from maps of Hampshire in the Map Collection. The longitude is expressed in degrees and decimal minutes; the readings are in map date order.
Bertius 1616 19° 24' E
Bill 1626 23° 9.5' E
Morden 1695 1° 17.5' W
Morden 1708 1° 10.3' W
Moll 1724 1° 17.4' W
Cowley 1743 1° 11.3' W
Simpson 1746 1° 17.2' W
Hutchinson 1748 1° 20.0' W
Kitchin and Jefferys 1749 1° 10.9' W
Kitchin 1750 1° 14.4' W
Kitchin 1751 large 1° 13.5' W
Kitchin 1751 small 1° 15.2' W
Bowen 1755 1° 11.1' W
Kitchin 1763 1° 13.4' W
Hogg 1784 1° 13.6' W
Harrison 1788 1° 14.3' W
Lodge 1788 1° 13.6' W
Cary 1789 1° 8.6' W
Tunnicliff 1791 1° 18.4' W
Tunnicliff 1791 1° 24' W
Baker 1792 1° 12.5' W
Faden 1796 1° 18.3' W
Cooke 1802 1° 17.0' W
Wilkes 1806 1° 12.6' W
Cary 1809b 1° 16.7' W
Cole and Roper 1810 1° 17.8' W
Wallis 1810 1° 18.2' W
Wallis 1810 1° 18.5' W
Wallis 1812 1° 17.5' W
Rowe 1816 1° 17.1' W
Robins 1819 1° 12.6' W
Pigot 1828 1° 18.4' W
Greenwood 1829 1° 18.5' W
Darton 1830s 1° 17.1' W
Murray 1830 1° 17.7' W
Lewis 1831 1° 17.4' W
Hall 1833 1° 21.1' W
Hall 1833 1° 21.5' W
Pinnock 1833 1° 18.9' W
Bell 1834 1° 8.8' W
Dugdale 1835 1° 18.7' W
Pigot 1835 1° 16.6' W
Walker 1837 1° 18.4' W
Hughes 1840 1° 18.3' W
Fisher 1845 1° 18.6' W
Ramble 1845 1° 14.9' W
Wyld 1846 1° 18.2' W
Cruchley 1856 1° 16.8' W
Hughes 1860s-70s 1° 18.4' W
Dispatch 1863 1° 18.8' W
Letts 1884 1° 18.2' W
Pratt 1905 1° 18.6' W
Bacon 1907 1° 18.8' W
The measurements were made from a large .jpg image of the map and are good estimates, but no better.

The accepted position of Winchester is:-
1° 18.4' W
from the Greenwich Meridian. I am not sure what is the centre position of Winchester. I have read the 'middle' of the city as shown on the maps.

Readings away from the correct number might indicate:-
  • error in my reading
  • error in the map maker's plotting
  • a different prime meridian
The last is the interesting possibility.


Two Early Maps

The two early readings use prime meridians out in the Atlantic. Bertius's map, 1616, perhaps uses the Canary Islands. Bill's map, 1626, probably uses the Cape Verde Islands.

Maps 1695 Onwards

The readings from maps of Morden 1695 onwards are plotted in a histogram, drawn with counts grouped in .3 minute longitude intervals. Measurements are not much better than +-.2minutes, some are worse than that!

Longitude of Winchester


1° 24.1'      X
1° 23.8'      
1° 23.5'      
1° 23.2'      
1° 22.9'      
1° 22.6'      
1° 22.3'      
1° 22.0'      
1° 21.7'      
1° 21.4'      X
1° 21.1'      X
1° 20.8'      
1° 20.5'      
1° 20.2'      
1° 19.9'      X
1° 19.6'      
1° 19.3'      
1° 19.0'      X
1° 18.7'      XXXXX
1° 18.4'      XXXXXXXX
1° 18.1'      XXX
1° 17.8'      XX
1° 17.5'      XXXX
1° 17.2'      XXX
1° 16.9'      XX
1° 16.6'      XX
1° 16.3'      
1° 16.0'      
1° 15.7'      
1° 15.4'      
1° 15.1'      X
1° 14.8'      X
1° 14.5'      X
1° 14.2'      X
1° 13.9'      
1° 13.6'      XXXX
1° 13.3'      X
1° 13.0'      
1° 12.7'      XX
1° 12.4'      X
1° 12.1'      
1° 12.0'      
1° 11.7'      
1° 11.4'      X
1° 11.1'      X
1° 10.8'      X
1° 10.5'      
1° 10.2'      X
1° 9.9'       
1° 9.6'       
1° 9.3'       
1° 9.0'       
1° 8.7'       XXX
1° 8.4'
There are too few readings to get sure conclusions from this tabulation. BUT: a few guesses are possible.

The obvious cluster is around 1° 18.4' W, which corresponds to the Greenwich meridian.

There could, perhaps should, be clusters at about 1° 17.2' W, 1° 14.6 W, 1° 13.6' W, 1° 12.7' W, 1° 11.0' W, 1° 8.7' W. corresponding to prime meridians in different parts of London.

A meridian at St Paul's would put Winchester at 1° 13.3' W, so the spread of readings from 1° 12.7 to 1° 15.1' W might reflect the use of this meridian.

Clustering can occur as a result of copying.

(A scatter diagram of minutes against quarter century was no more informative.)