Re: Flat Earth Chronology

[brian whatcott <inet@INTELLISYS.NET>]

At 19:24 10/24/99 -0700, you wrote:
> Can someone please give a chronology of the belief in a flat Earth.
> Egyptians? Babylonians? Hebrews? Chinese? Old Testament? Etc?
>
> When did belief in a spherical like Earth become common?
>
> Jim Green
> mailto:JMGreen@sisna.com
> http://users.sisna.com/jmgreen

I cannot speak to beliefs, but I can say that it was advantageous
to navigators to act on the basis of plane maps for many centuries.
 "Sailings" are the means used to deduce present position, given
likely values for course and distance run.

"Plane-sailing" in particular, continues to be used even at the
present time, with the advantage of Mercator charts, given course
and distance for moderate distances.

Though the direction is laid off from an adjacent
 meridian, the Mercator map projection largely accounts for the
convergence of the meridians. However, on the plane charts used
formerly, serious errors arose when a line of position was drawn
at a fixed angle from a local meridian.
This is the error arising from treating a spherical surface as flat.

 Bowditch mentions the contributions of Thales, Hipparchus, Napier,
 Wright and others in contributing formulas leading to tables for
various refinements of plane sailing - via traverse,
middle-latitude, Mercator, and forward into great circle sailings.

Sincerely

brian whatcott <inet@intellisys.net>
Altus OK