--- Begin Forwarded Message ---
Date: Tue, 13 Feb 2001 16:44:44 +0000
From: "R.B.Parry" <[log in to unmask]>
Subject: Re: MAP QUESTION!
Sender: "R.B.Parry" <[log in to unmask]>



It doesn't really matter whether you place latitude or longitude first
because it should always be clear which is which, i.e. you always state
latitude so-and-so and whether it is north or south of the Equator, and
longitude so-and-so and whether it is east or west of the Prime Meridian.
So it should always be clear.

The same is not true of a grid reference which does not usually incorporate
such clues. So in this case it is vital to follow the Cartesian convention
of x, y.

I also observe that there is a convention in America to refer to the
latitude and longitude graticule as a grid, whereas I think over here we
usually make a distinction between graticule (which when transformed by
projection may have curved lines) and a grid which is always rectangular,
having been superimposed on to the projected map.

Bob Parry

Johnnie Sutherland wrote:

> Hello Maps-L:
>       The question on how to describe the lat/long of a place is
> interesting in that it may involve more than appears on the surface. At
> first look there is the confusion between a local grid and the
> geographical grid.  That is between an arbitrary reference grid of
> lines superimposed over a geographical area, and geographical
> coordinates tied to the earth, longitude and latitude.  The local grid
> is probably going to be read as you would read cartesian coordinates, x
> then y.  In the question on Maps-L the x and y of the local grid are
> being seen as latitude and longitude.  That is an incorrect way to see
> the coordinates as they are not lat/long lines.  But the question does
> raise the difference in stating lat/long or long/lat in other
> situations.
>      In the U.S. it does appear than many use the form of latitude
> first, then longitude.  For example look at Robinson and Sale,
> "Elements of Cartography," used on most (older) American Geographers as
> a beginning level textbook, states "...on the earth's coordinate
> system, latitude is usually given first."  Most authors use the phrase
> "latitude and longitude," not "longitude and latitude"  Yet if you look
> in a newer text, like Muehrckes' "Map Use" you will see positions cited
> by longitude then latitude.  In the same paragraph the Muehrckes cite a
> place by longitude then latitude and then use the phrase "latitude and
> longitude."
>      In Ptolemy's "Geography" he puts longitude first, according to
> Dilke, "...since he expected the mapmaker to draw the map from left to
> right."  In looking at some British WWI trench maps I noted that
> positions in the military grid were to be cited easting first, then
> northing.  The same system, east reading, then north, is used for the
> UTM system.
>     So do we have a problem of Europens reading a position long/lat and
> Americans reading it as lat/long?  Is it a problem of definations?
> Is it a problems of different groups, geographers vs surveyors, using
> a system in different ways?  Or is it a problem of how we use language
> - in our language we say "latitude and longitude" but we state a
> position by longitude then latitude (maybe because Ptolmey?).
>
> John Sutherland
> University of Georgia
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