The Supposed Circumnavigation of Earth

Many people foolishly imagine that ships can sail in a
straight line due E. or W, ; but if a line be drawn, all round
a sphere, it would make a circle, a chalk mark round a football
for instance. A circle is not a straight line, as I once had
reason to remind an educated gentleman in a public debate.
He was known, too, as “ the Leicester astronomer!”

In the above figure the magnetic north “pole” is represented
at N ; and if a ship, sailing round the outer circumference,
keeps the point of the compass always towards N,
and steers at right-angles to it the course described will be
a circle.

A small flat island could be circumnavigated in the same
way, with a powerful magnet in the middle of the island ;
the ship thus describing a circle. But if a vessel took a
straight line course from A, it would sail in the south-westerly
direction towards S.W.

On a globe it would be impossible for the horizontal needle
always to point to the north magnetic “ pole ” from different
parts of a spherical sea, as anyone may prove by laying a
needle at various points as a tangent to a large ball. But
on a flat surface the needle always points to the centre
while the ship describes a circle— which double fact not only
again explodes the globular theory, but establishes the truth
of a plane earth and sea!

We have years ago many times pointed out this fact in
our literature, and as a result one professor has had the
honesty to make the following confession;

“The earth has been circumnavigated a great many times…
We can (we could ?) journey round the globe, sometimes travelling on
land, and sometimes on the sea. This would appear to be
a certain proof that the earth’s surface is curved. Nevertheless it has
been pointed out that circumnavigation would be possible if the earth
had A FLAT SURFACE with the north magnetic pole at its centre.
A compass needle then, would always point to the centre of the surface,
and so a ship might sail due east and west, as indicated by the compass,
and eventually return to the same point by describing a circle.” (Caps,
mine.) Prof. R.A. Gregory, F.R.A.S., Elementary Physiography’.
Yet thoughtless teachers still refer to the schoolboy proof
that circumnavigation proves the earth a globe!