Re: anachronisms?

: bernardz <bernardz@[EMAIL PROTECTED]
>
: If you read the article I quoted you can see that Columbus took that
: into account  in an area he knew nothing about.

Um.  No.  The people who created that chart corrected Columbus' 
incorrect figures.

    http://www.newworldexplorersinc.org/EarlyNavigation.pdf
    The actual track over the bottom, as corrected for fifteenth-century
    magnetic variation, Columbus s Genoese mile and nautical mile
    differential, and effect of the ocean currents, is shown as a solid
    line with a dot at day s end.  This chart graphically illustrates
    why historians wrongly conclude that Columbus s log is inaccurate,
    since the uncorrected (or improperly corrected) track plotted
    directly from the data in the log (dotted line) ends a considerable
    distance northeast of any possible island landfall.  When corrected
    for influencing factors, - unknown to Columbus, - the data in the
    log is then revealed as accurate, and leads to San Salvador as the
    landfall island in his 1492 discovery voyage. 

This is saying that Columbus' estimated position at the end of the voyage
was considerably off.  When corrected by ocean currents and variations in
magnetic north that we know about but that Columubus didn't, the accuracy
is radically improved.  Columbus' log accurately reflects his velocities
wrt the local ocean surface (and relative to magnetic north)... and even
with that, he ended up hundreds of kilometers away from where he thought
he was.


Wayne Throop   throopw@[EMAIL PROTECTED]
   http://sheol.org/throopw