r he would have to sail towards the rising
sun, and would find the climate getting colder as he approached
Byzantium. So, too, he might roughly guess that Marseilles was
somewhere to the west and north of him; but how was he to fix the
relative position of Marseilles and Byzantium to one another? Was
Marseilles more northerly than Byzantium? Was it very far away
from that city? For though it took longer to get to Marseilles,
the voyage was winding, and might possibly bring the vessel
comparatively near to Byzantium, though there might be no direct
road between the two cities. There was one rough way of determining
how far north a place stood: the very slightest observation of the
starry heavens would show a traveller that as he moved towards
the north, the pole-star rose higher up in the heavens. How much
higher, could be determined by the angle formed by a stick pointing
to the pole-star, in relation to one held horizontally. If, instead
of two sticks, we cut out a piece of metal or wood to fill up the
enclosed angle, we get the earliest form of the sun-dial, known as
the _gnomon_, and according to the shape of the gnomon the latitude
of a place is determined. Accordingly, it is not surprising to find
that the invention of the gnomon is also attributed to Anaximander,
for without some such instrument it would have been impossible for
him to have made any map worthy of the name. But it is probable
that Anaximander did not so much invent as introduce the gnomon,
and, indeed, Herodotus, expressly states that this instrument was
derived from the Babylonians, who were the earliest astronomers, so
far as we know. A curious point confirms this, for the measurement
of angles is by degrees, and degrees are divided into sixty seconds,
just as minutes are. Now this division into sixty is certainly
derived from Babylonia in the case of time measurement, and is
therefore of the same origin as regards the measurement of angles.

We have no longer any copy of this first map of the world drawn
up by Anaximander, but there is little doubt that it formed the
foundation of a similar map drawn by a fellow-townsman of Anaximander,
HECATAEUS of Miletus, who seems to have written the first formal
geography. Only fragments of this are extant, but from them we are
able to see that it was of the nature of a _periplus_, or seaman's
guide, telling how many days' sail it was from one point to another,
and in what direction. We know also that he a