The torque estimate you shared is, as I understand it, only for one version of the aeolipile—the famous one with the spinning hollow ball with nozzles. That version is often referred to as theaeolipile, which it is not. It is simply one variant of it, and certainly not the one that people used most commonly, which was the much simpler “philosophical bellows” or blowing face form that I illustrated. I think we’d need a different estimate of the torque from a more ordinary aeolipile, e.g. the one portrayed by Branca directed at vanes. I suspect this is also very low, but it’s worth clearing up this very common confusion.
I don’t think it’s correct to say that the Newcomen engine’s breakthrough was that it provided motion. It was still essentially applied to exactly the same things that the Savery engine was—pumping, occasionally with additional pumping-derived mechanical uses like using the pumped water to drive a waterwheel. It is the Watt engine, not the Newcomen engine, that made the breakthrough in directly supplying essentially any any industrial power need (although arguably the Watt engine is an improvement on the Newcomen one, it took over a half a century for it to be developed from it).
In terms of the jump to universality, I certainly had our conversations on this at the back of my mind when writing! One thing I really wanted to show is how people had already been experimenting with or at least considering using thermal energy (steam, and flue effects above fires) for a very wide range of mechanical uses already, and in Part II I will do something similar for applications of atmospheric pressure (though this is still under investigation). At the very least, from this post, I think I’ve demonstrated that the idea of universality from such power sources was nothing new.
An additional note: I’m not sure that torque estimates are necessarily the correct measure to compare the different engines, especially considering their various applications. Comparing the spinning hollow ball with nozzles with Watt’s engine seems completely nonsensical to me—it’s projecting back onto something that was not intended to be used that way at all. It’s presentist bias (something that we need to be especially wary of when studying technological pathways). One of the best theories about what Hero’s device was actually used for is not that it was some toy, but a scientific demonstration in the big debate on the source of the wind (a major debate well into the 17thC). So it’s not comparing like with like. As for comparing Savery and Newcomen, neither of them were used for torque (other than when they pumped for waterwheels, which should make no difference between them). Instead, we need to look at volume of water raised. But even this measure is complicated by all sorts of other factors like very different capital costs (Savery engines were much much cheaper), fuel consumption, and the space required for the engines. This requires further research, however. The Savery engine is in my opinion still very under-researched.
Thanks Anton! Let me step back a bit and clarify where I’m coming from.
I don’t know where you’re going with this, but there are a few kinds of conclusions you might end up on:
Which invention was the most important one, the one that deserves to be called out on our historiographic timelines (did Newcomen “really” invent the steam engine, or was it Savery, or was it de Caus, etc.)
Whether the steam engine “could have been” invented earlier (maybe even in ancient Rome)
Whether science was “needed” to invent the steam engine
And what I’m saying is that in considering those topics, it’s crucial to consider (1) the universality of the mechanism and (2) the amount of force that can be generated (not to mention other factors such as the fuel efficiency and therefore the cost of operation).
It could be that many types of machines operated by steam and/or air pressure for a long time, but if for practical reasons they couldn’t be applied to a wide range of industrial purposes, and if some later design change was needed to achieve that, then I think said design change is what deserves to be called out as the key invention.
I’m sure I’m not telling you anything you don’t already know, just harping on a pet issue of mine.
Step back a bit?! But I like it down here in the weeds!
That’s a very useful way to separate out two issues here, and helps me to clarify what I’m up to.
My main focus is on whether atmospheric pressure exploitation is older than the standard historiography suggests. Hence the choice of title, about whether the steam engine could have been invented earlier.
Part I is really about setting up 1) the pretty uncontroversial claim that it is atmospheric pressure and not steam itself that is the key issue of debate here, because of how human energy exploitation actually developed, and 2) making the slightly more controversial claim that we need to look at industrial atmospheric pressure exploitation in general, and not to focus solely on the Newcomen variant of it.
This is not really to make an argument about what the “real, first” steam engine is, but only to point out that Newcomen’s and Savery’s models were effectively parallel technologies, both in use c.1700-70, and exploiting the same natural phenomenon in very similar ways—both of them, according to the standard historiography, stemming from the discovery of atmospheric pressure. The reason I play up the Savery engine is also because the Newcomen engine has been overemphasised in people’s minds because of its later development by Watt, and not because of what the Newcomen engine itself actually achieved prior to Watt.
Now, I do briefly raise the possibility of a Newcomen engine, and thus a Watt engine, being eventually derived from a Savery engine. I do believe this to be true, and will probably write a sort of Part III arguing this case more fully, but for now I just wanted to narrow the focus of my “why not earlier” question, as I’m looking at it, on how early someone could have successfully exploited atmospheric pressure for industrial use.
Lastly, on science, I see this as a sort of sub-question, though I ought to clarify it in Part II. I’m not at all arguing that “science” was unimportant, as scientia just means knowledge after all. It’s about precisely which knowledge—in this case, whether successful industrial-scale exploitation of atmospheric pressure needed to have stemmed from the discoveries of Torricelli, von Guericke, Huygens, Boyle, and Papin specifically.
Thanks Jason,
Great comments.
The torque estimate you shared is, as I understand it, only for one version of the aeolipile—the famous one with the spinning hollow ball with nozzles. That version is often referred to as the aeolipile, which it is not. It is simply one variant of it, and certainly not the one that people used most commonly, which was the much simpler “philosophical bellows” or blowing face form that I illustrated. I think we’d need a different estimate of the torque from a more ordinary aeolipile, e.g. the one portrayed by Branca directed at vanes. I suspect this is also very low, but it’s worth clearing up this very common confusion.
I don’t think it’s correct to say that the Newcomen engine’s breakthrough was that it provided motion. It was still essentially applied to exactly the same things that the Savery engine was—pumping, occasionally with additional pumping-derived mechanical uses like using the pumped water to drive a waterwheel. It is the Watt engine, not the Newcomen engine, that made the breakthrough in directly supplying essentially any any industrial power need (although arguably the Watt engine is an improvement on the Newcomen one, it took over a half a century for it to be developed from it).
In terms of the jump to universality, I certainly had our conversations on this at the back of my mind when writing! One thing I really wanted to show is how people had already been experimenting with or at least considering using thermal energy (steam, and flue effects above fires) for a very wide range of mechanical uses already, and in Part II I will do something similar for applications of atmospheric pressure (though this is still under investigation). At the very least, from this post, I think I’ve demonstrated that the idea of universality from such power sources was nothing new.
An additional note: I’m not sure that torque estimates are necessarily the correct measure to compare the different engines, especially considering their various applications. Comparing the spinning hollow ball with nozzles with Watt’s engine seems completely nonsensical to me—it’s projecting back onto something that was not intended to be used that way at all. It’s presentist bias (something that we need to be especially wary of when studying technological pathways). One of the best theories about what Hero’s device was actually used for is not that it was some toy, but a scientific demonstration in the big debate on the source of the wind (a major debate well into the 17thC). So it’s not comparing like with like. As for comparing Savery and Newcomen, neither of them were used for torque (other than when they pumped for waterwheels, which should make no difference between them). Instead, we need to look at volume of water raised. But even this measure is complicated by all sorts of other factors like very different capital costs (Savery engines were much much cheaper), fuel consumption, and the space required for the engines. This requires further research, however. The Savery engine is in my opinion still very under-researched.
I look forward to debating the next one!
Thanks Anton! Let me step back a bit and clarify where I’m coming from.
I don’t know where you’re going with this, but there are a few kinds of conclusions you might end up on:
Which invention was the most important one, the one that deserves to be called out on our historiographic timelines (did Newcomen “really” invent the steam engine, or was it Savery, or was it de Caus, etc.)
Whether the steam engine “could have been” invented earlier (maybe even in ancient Rome)
Whether science was “needed” to invent the steam engine
And what I’m saying is that in considering those topics, it’s crucial to consider (1) the universality of the mechanism and (2) the amount of force that can be generated (not to mention other factors such as the fuel efficiency and therefore the cost of operation).
It could be that many types of machines operated by steam and/or air pressure for a long time, but if for practical reasons they couldn’t be applied to a wide range of industrial purposes, and if some later design change was needed to achieve that, then I think said design change is what deserves to be called out as the key invention.
I’m sure I’m not telling you anything you don’t already know, just harping on a pet issue of mine.
Step back a bit?! But I like it down here in the weeds!
That’s a very useful way to separate out two issues here, and helps me to clarify what I’m up to.
My main focus is on whether atmospheric pressure exploitation is older than the standard historiography suggests. Hence the choice of title, about whether the steam engine could have been invented earlier.
Part I is really about setting up 1) the pretty uncontroversial claim that it is atmospheric pressure and not steam itself that is the key issue of debate here, because of how human energy exploitation actually developed, and 2) making the slightly more controversial claim that we need to look at industrial atmospheric pressure exploitation in general, and not to focus solely on the Newcomen variant of it.
This is not really to make an argument about what the “real, first” steam engine is, but only to point out that Newcomen’s and Savery’s models were effectively parallel technologies, both in use c.1700-70, and exploiting the same natural phenomenon in very similar ways—both of them, according to the standard historiography, stemming from the discovery of atmospheric pressure. The reason I play up the Savery engine is also because the Newcomen engine has been overemphasised in people’s minds because of its later development by Watt, and not because of what the Newcomen engine itself actually achieved prior to Watt.
Now, I do briefly raise the possibility of a Newcomen engine, and thus a Watt engine, being eventually derived from a Savery engine. I do believe this to be true, and will probably write a sort of Part III arguing this case more fully, but for now I just wanted to narrow the focus of my “why not earlier” question, as I’m looking at it, on how early someone could have successfully exploited atmospheric pressure for industrial use.
Lastly, on science, I see this as a sort of sub-question, though I ought to clarify it in Part II. I’m not at all arguing that “science” was unimportant, as scientia just means knowledge after all. It’s about precisely which knowledge—in this case, whether successful industrial-scale exploitation of atmospheric pressure needed to have stemmed from the discoveries of Torricelli, von Guericke, Huygens, Boyle, and Papin specifically.