XX
ALGEBRA: DIOPHANTUS OF ALEXANDRIA
Beginnings learnt from Egypt,
In algebra, as in geometry, the Greeks learnt the beginnings
from the Egyptians. Familiarity on the part of the Greeks
with Egyptian methods of calculation is well attested. (1)
These methods are found in operation in the Heronian writings
and collections. (2) Psellus in the letter published by Tannery
in his edition of Diophantus speaks of ‘ the method of arith
metical calculations used by the Egyptians, by which problems
in analysis are handled ’; he adds details, doubtless taken
from Anatolius, of the technical terms used for different kinds
of numbers, including the powers of the unknown quantity.
(3) The scholiast to Plato’s Charmides 165 e says that ‘parts
of XoyuTTLKrj, the science of calculation, are the so-called Greek
and Egyptian methods in multiplications and divisions, and
the additions and subtractions of fractions (4) Plato himself
in the Laws 819 A-c says that free-born boys should, as is the
practice in Egypt, learn, side by side with reading, simple
mathematical calculations adapted to their age, which should
be put into a form such as to combine amusement with
instruction: problems about the distribution of, say, apples or
garlands, the calculation of mixtures, and other questions
arising in military or civil life.
‘ Han ’-calculations.
The Egyptian calculations here in point (apart from their
method of writing and calculating in fractions, which, with
the exception of §, were always decomposed and written
as the sum of a diminishing series of aliquot parts or sub
multiples) are the /mu-calculations. Hau, meaning a heap, is
the term denoting the unknown quantity, and the calculations