XXXli ADDITIONAL NOTES. .
P. 325. A military mountain climb
From the pen of Arrian (Anabasis, 4. 18, 19) we possess a
description of an escalade by Alexander's troops in Sogdiana.
With the help of iron tent-pegs, which they fixed into the frozen
snow on the mountain side, and of linen ropes, with which they
hauled each other up like modern Alpinists, Alexander's cragsmen
clambered to the summit of an impregnable fortress. They lost
thirty men in the ascent, but had the satisfaction of obtaining the
surrender of the dumbfounded garrison, and of bringing in to
Alexander a captive princess, Roxane, whom the king took to
wife.
Pp. 328-335. Ancient signals
For a fuller treatment of this subject, see W. Riepl, Das Nach-
richtenwesen des Altertums^ pp. 25 ff., 43 IT., 91 ff.
Pp» 335> 336- Measurement of mountains
The philosopher Thales (c. 600 B.C.) was said to have ascertained
the height of an Egyptian pyramid by measuring (i) the shadow
of the pyramid, from the half-way point on its base, (2) his own
shadow, (3) his own height. A simple application of the rule-of-
three gave him the height of the pyramid.
Ch. 16. Ptolemy
A text of Ptolemy's Geography, with a Latin transla tion, notes and
maps", has been provided by C. Miiller (1883-1901). For a recent
discussion of Ptolemy's methods see 0, Cuntz, Die Geographie des
Ptolemaios.
After the decline of classical antiquity the Geography of Ptolemy
continued to be studied in the Islamic countries, The appearance
of a Latin translation in 1410 gave a great impetus to geographical
studies in Europe, and to renewed exploration of the world.
Pp' 341* 342- Ptolemy's error about the length of
the habitable world
In estimating the length of Eurasia at not less than 180°, Ptolemy
unwittingly gave support to Seneca's wild surmise that a voyage
from Spain to India would take 'very few days7 (Quaestiones
Naturales, prologue, § 13). The fifteenth-century quest for an