Wonder, Sorcery, and Technology: Contribute to the History of Medieval Robotics - History of Computing: Learning from the Past - page 20

The story is very interesting from several points of view.
First of all, the palace designer had planned the system in order to kill any thieves
or at least to give them a moral lesson, not to impress them with the automata's capa-
bilities. We have the description of an actual distributed system made up of automata:
they are all running the same task (stop the intruders, if they are stealing something).
The actions performed by the automata are not periodical: they begin and end depend-
ing on values measured by “sensors”. Nothing is said about how the system reverts to
its initial state after the departure of the intruders.
Then, in Hero's Pneumatics (I, 41), an automaton composed by two figures, enti-
tled Hercules and the Snake , is described: when a user lifts an apple (placed between
the statue of the archer Hercules and the tree the snake is wrapped around) Hercules
shoots with an arrow the snake, which in the meanwhile begins to hiss. Its operation is
relatively simple: the base of the group is divided horizontally into two parts (the top
compartment is full of water), connected by a drain hole, where a cork is set. By rais-
ing the apple, a double synchronous effect is produced:

1. a chain, connected to the apple, pulls the cork from the hole, causing the gur-

gling through the various ducts that is similar to a snake hiss;

2. a second chain, also connected to the apple, acts on the figure of Hercules,

making him stretch and release the string of his bow.

In addition, in a French romance, whose first written version dates to the middle of
the 12 th century, entitled Le pèlerinage de Charlemagne (Charles the Great's Pilgrim-
age), the setting of the emperor's main adventure is the vaulted and circular palace of
Hugon, emperor of Constantinople, where Charles and his 12 peers are housed as
guests in a beautiful bed-chamber, full of precious decorations and refined objects.
The light source is a carbuncle, set on a pillar [21]. The front of the palace is deco-
rated with the statues of two smiling young men, holding ivory horns. Whenever a
wind comes up, these images blow their horns, producing a loud clear sound, and
immediately the palace begins rotating. A carbuncle and a moving room appear also
in the 14 th -century allegorical poem titled Σοφροσύνη (Temperance) by Theodore
Meliteniotes [22]. Here we also find an abridged version of a lapidary, a book where
stones are put in relation with moral qualities: the carbuncle is a symbol for temper-
ance, a cardinal virtue, related to self-control.
Last, but not least, remark: Gerbert is told to have designed and built a water organ,
during his stay in Reims; his treatise on the subject has been recently studied [23].
Even taking into consideration that this is a legendary episode, one cannot but be
struck by the strong similarity between this system and the Heronian automaton,
which may have been the remote source of the story, though it was considered neither
in the Arabic written tradition nor in the Byzantine implementations.
It is therefore reasonable to make two assumptions, not mutually exclusive:

1. This knowledge was transmitted within the workshops by the masters to their

apprentices from the Antiquity to the Middle Ages with or without Arabic
contribution; it is unfortunately very hard to prove such an assumption, due
to the lack of sources.

2. A Latin cultured tradition, mostly separated from the Arabic one, existed,

and flourished, probably in the monasteries; this second assumption could be
easier to prove, by means of a census of Latin manuscripts on the subject.