An early Dutch computer: Willem Bartjens
Willem Bartjens was the author of an arithmetic textbook
'Cyferringe' (Arithmetic) famous - or notorious? - in the
Netherlands. It was reprinted many times during two centuries:
first appearing in 1637, the last edition was printed in 1839.
Bartjens' name is still quoted in phrases expressing the
obviousness of a result, like 'According to Bartjens, two and two
Bartjens was a 'computer' in the original meaning of the word,
i.e. a person doing computations. Therefore the game on the back of
the Computer Museum's copy of Cyfferinge is an early example of a
computer game! The game (a simple example of a magic square) is
Rephrased in modern language, the text runs as follows:
"In conclusion, an amusing computation which always gives 24
whether the numbers are added along a diagonal, a row or a
For any other desired sum x, first compute y = x/3, then enter the
following numbers in row order in the fields of the square: y+3,
y-2, y-1, y-4, y, y+4, y+1, y+2, y-3.
Having done well was all my heart's desire: is
it not as it should be, my heart will be hurt.