Awhile back I was watching a documentary on religious machines that were built by the ancient Greeks and Romans; and these were essentially machines that were used to give the impression of miracles to people in temples, and involved things like making statues cry or bleed among other things. They obviously don’t have working machines, and were building replicas/models of these machines from a combination of descriptions of their use and artefacts from them; while using materials and techniques that these cultures were known to have.
One of the things that struck me about this was that (if the models were even remotely accurate) these machines demonstrated that we had the understanding and technology to build a steam engine over a thousand years before we ever built one. While the show didn’t approach this topic at all, it did (indirectly) give some reasons why this would be the case.
These religious machines were typically built in secret with all the technology that was used in making them kept secret from both the general public as well as other machine builders at other temples/cults. This meant that different groups were constantly being forced to re-invent the wheel (figuratively speaking), and it was very easy to lose significant knowledge about something if a war or plague killed off several expert machine builders. Basically, the fact that there was a constant effort to re-discover the same knowledge meant that the ancients were very inefficient.
The other reason I came up with was that the ancient Romans and Greeks really had no reason to build a steam engine. Building a machine that does the work of ten men becomes less worthwhile unless it is less expensive and more reliable; and in an era of slaves this becomes an unlikely situation. To make matters worse, metal work throughout history has been remarkably expensive and (relatively speaking) I would suspect that it was far more expensive in the time of the ancient Greeks and Romans, which would make the steam engine an item that could never be cost effective.
The reason I bring this up is that it is entirely possible that thousands of years before the Ancient Roman and Greeks there were cultures that were working with more advanced technologies than we would give them credit for; especially if you’re talking about the work that could be handled by a handful of people in a small work-shop (or something). Beyond that, we’re constantly re-discovering technology that was used by the ancients to do things which seemed far beyond their means; an example of this is that the Romans had seem-less marble joins on many of there temples which requires a precision far beyond what we thought they were capable of, but they speculate that some of this is possible simply because the Romans used brute-force to slowly grind down the stone with sand to get this amazing precision.
