The legacy of Alexander is somewhat mixed insofar as innovation is concerned. To his credit there is the city of Alexandria, with its cultural diversity and intellectual fertility. Of course there is also Archimedes, founder of hydrostatics and supposed inventor of the “Archimedes screw”. There is also Ctesibios, inventor of the fire pump. But other innovations never really emerged from their cocoons to find practical application. These include the aeolipile (wind ball) of Heron, a device whose further development could easily have led to the steam engine. There were many other such inventions, and seemingly useless gadgets, that were destined to be investigated or rediscovered by Arab scientists or, even later, by Leonardo da Vinci and other great thinkers of the Renaissance. Even during the shining period of Alexandria, the greatest innovations seem to have risen from obscurity, from the shadows, from anonymous inventors. The paddle wheel, the water mill, the noria are all born somewhere in the Orient and then progress through history silently, leaving traces of their passage only by chance, here in a description by Strabo, there in a Greek poem…. The windmill is not conceived in the great library of Baghdad but in the Persian countryside. Also in China, nursery of innovation from the 3rd century through the end of the Middle Ages, inventions come from a few obscure civil servants such as Tu Shih, who “loved the common people and wanted to lighten their work”, and to this end brought hydraulic energy to the forges. Or Chiao Wei Ho who invented the lock to avoid damaging boats that had to be dragged from one section of a channel to another. Or such as the anonymous inventor who developed the axial rudder for ships. These innovations did not come from the minds of scholars working in imperial courts.
From the above observation, one has to ask: of what use are teams of scientists and research institutes? Where these existed in ancient times, they were instrumental in the spread and standardization of useful inventions, fostering the rapid refinement and optimization of new devices, ensuring that optimal configurations and designs were adopted in practice. The dimensions of the Chinese “dragon backbone machine” were standardized from the 9th century on. Without manuals and other technical documentation, the dissemination of technical innovation is an extremely slow process — errors are repeated, and the “optimal” design develops very slowly. The Roman aqueducts are characterized by surprising conceptual flaws given the experience that could and should have been accumulated. Similarly Roman dams are sometimes well conceived, but just as often are very badly designed. The arch dam seems to have been “re-invented” many times over.
Innovations transcend the boundaries of civilizations. But lacking written traditions, their dissemination and spread is extremely slow. Perhaps the most significant example of this is the spread of the qanat, the device for tapping groundwater that is so simple in principle, if not in application. Conceived in Armenia or in Persia between the 10th and 8th century BC, it is spread into the Orient by the Persians, and is further developed by the Romans who take it to Lybia and Tunisia. But Morocco does not see the qanat until it has made at least two other journeys: one with the westward migration toward the Saharan oases, and another that comes from Muslim Spain to Morocco following the Reconquest.
In the absence of written descriptions, such technical devices tend to be developed differently from one locality to another, reflecting the vicissitudes of oral transmission of know-how rather than the best adaptation of the technology to the local situation. The water mill has a horizontal wheel in the China and the Arab world, but a vertical wheel in the Occident, and the same is true of the windmill at a much later period. The sail rigs on Chinese junks, so perfectly adapted to the needs of coastal commerce in China, do not spread into the West where oarsmen perish in the galleys.
