1 The Birth of Science - MSRI

4.7 Use of Natural Power 109
the third century. 107 Most scholars think the invention of the water mill
dates from around 100 B.C., but recently M. J. T. Lewis has argued that this
was one of the first products of Hellenistic science, owed to Alexandrian
scientists of the first half of the third century B.C. 108
Wind. The origins of the windmill are obscure. The earliest documented
specimen was built on the orders of Caliph Omar I (634–644) by a Persian
who had declared he was able to do it. However, it is likely that in
Sistan (the southwestern part of today’s Afghanistan) windmills predated
Islam. 109
Heron, in discussing a pipe-organ moved by a wheel with paddles, describes
the wheel by saying it’s similar to an anemourion (), evidently
something the reader was expected to be familiar with. 110 The word
(a compound whose first part means wind) is not otherwise attested as a
common noun, but the context makes it clear that it means something that
uses the wind to create rotational motion: in the manuscripts the passage
is illustrated with drawings showing the organ with its paddle-wheel,
which moves a piston (Figure ??).
The same word was in Antiquity also a place-name — given, for example,
to two promontories in Cilicia. 111 In this capacity its likely meaning
would of course be “windmill”, a conspicuous landscape feature (unless
there was a homonym that happened to mean “windy mountain”).
Many scholars have felt that the Heronian passage can be disregarded
because it is not confirmed by other writings. Heron presumably mentioned
the anemourion in a moment of distraction, forgetting that it had page 150
not been invented yet. We know that he was given to such lapses.
Steam. Heron describes two steam engines: a demonstration model (the
aeolipile, an enclosed round vessel with curved vents through which steam
generated inside the vessel came out, causing it to revolve), and a device
used to open the doors of a temple when a fire was lit. 112 Heron’s steam
engines have generally been considered oddities built just to amaze, but if
we consider their construction in the framework of a civilization that had
started to employ water power, they can be seen instead as arising from
a search for energy sources that do not depend on geographical accident
(see Section 4.9 for a fuller discussion).
107 [Lewis: MH], pp. 56–57.
108 [Lewis: MH], pp. 33–61. A summary of the arguments is given in [Lewis: HP], pp. 644–645.
109 [Hill: E], p. 784.
110 Heron, Pneumatica, I, xliii, 204, 16.
111 Strabo, Geography, XIV, v, 3; XIV, v, 5.
112 Heron, Pneumatica, II, xi; I, xxxviii.
Revision: 1.14 Date: 2002/10/24 04:25:47