Now, finally, we come to James Watt. Whatever credit he deserves, it is clear that he stood on the shoulders of a number of giants. Even if he had been capable of inventing the steam engine on his own, the plain fact is that he didn't. His grandfather was a mathematician - there seem to be a lot of mathematicians in the history of the steam engine - and Watt inherited his abilities. He carried out lots of experiments, and he made quantitative measurements, a relatively new idea. He worked out how heat travelled through the materials of the engine, and how much coal it took to boil a given amount of water. And he realised that the key to an efficient steam engine was to control unnecessary heat loss. The worst loss occurred in the cylinder that powered the piston, which kept changing temperature. Watt realised that the cylinder should always be kept at the same temperature as the steam that entered it - but how could that be done? The answer, when he finally chanced upon it, was simple and elegant: I had gone to take a walk on a fine Sabbath afternoon. I had entered the Green by the gate at the foot of Charlotte Street, and had passed the old washing-house. I was thinking upon the engine at the time, and had gone as far as the herd's house, when the idea came into my mind that, as steam was an elastic body, it would rush into a vacuum, and, if a communication were made between the cylinder and an exhausted vessel, it would rush into it, and might be condensed there without cooling the cylinder ... I had not walked farther than the Golfhouse, when the whole thing was arranged in my mind.
Such an easy thing to come up with - don't cool the steam in the cylinder, cool it somewhere else. Yet it improved the machine's efficiency so much that within a few years the only steam engines that anyone even thought of installing were those of Watt and his financial partner Boulton. Boulton-and-Watt engines cornered the market. No really significant improvements were subsequently made to their design. Or, to be more accurate, later `improvements' supplanted the steam engine with engines of a very different design, driven by coal and oil. The steam engine had evolved to the pinnacle of its existence, and what displaced it was, in effect, a new species of engine altogether.
In retrospect, steam engine time arrived around the period of Savery, when the ability to make practical machines coincided with a genuine need for them in an industry that could afford to pay for them and would make more profits as a result. Add to that a sound business mind, to notice the situation and exploit it, and a sense for publicity to raise money from investors and get the idea off the ground, and the steam engine went like a ... train.
Ironically, before most people realised that steam engine time had arrived, it had gone again, and in the end there was only one winner. The rest of the competition fell by the wayside. And that is why Watt gets so much credit, and why, ultimately, he deserves it. But he also deserves credit for his systematic quantitative experiments, his focus on the theory behind the steam engine, and his development of the concept - not as its inventor.
Certainly not for watching a kettle as a kid.
The history of the introduction of the Boulton-and-Watt steam engine is essentially an evolutionary one: the fittest design survived, the less fit were superseded and vanished from the historical record. Which brings us to Darwin, and natural selection. The Victorian era was `steam engine time' for evolution; Darwin was just one of many people who recognised the mutability of species. Does he deserve the credit he gets? Was he, like Watt, the person who brought the theory to its culmination? Or did he play a more innovative role?
In the introduction to Origin, Darwin mentions several of his predecessors. So he certainly wasn't trying to take credit for the ideas of others. Unless you subscribe to the rather Machiavellian school of thought that giving credit to others is just a sneaky way of damning them with faint praise. -One predecessor that he does not mention is perhaps the most interesting of all - his own grandfather, Erasmus Darwin. Perhaps Charles felt that Erasmus was a bit too nutty to mention, especially being a relative.
Erasmus knew James Watt, and may have helped him to promote his steam engine. They were both members of the Lunar Society, an organisation of Birmingham technocrats. Another was Josiah Wedgwood, Darwin's uncle Jos's grandfather and founder of the famous ceramics company. The 'Lunaticks' met once a month at the time of the full moon - not for pagan or mystic reasons, or because they were all werewolves, but because that way they could see their way easily as they rode home after a few drinks and a good meal.
Erasmus, a physician, could also turn a nifty hand to machinery, and he invented a new steering mechanism for carriages, a horizontal windmill to grind Josiah's pigments, and a machine that could speak the Lord's Prayer and the Ten Commandments. When the 1791 riots against `philosophers' (scientists) and for `Church and King' put paid to the Lunar Society, Erasmus was just putting the finishing touches to a book. Its title was Zoonomia, and it was about evolution.
Not, however, by Charles's mechanism of natural selection. Erasmus didn't really describe a mechanism. He just said that organisms could change. All plant and animal life, Erasmus thought, derived from living `filaments'. They had to be able to change, otherwise they'd still be filaments. Aware of Lyell's Deep Time, Erasmus argued that: In the great length of time, since the earth began to exist, perhaps millions of ages before the commencement of the history of mankind, would it be too bold to imagine, that all warm-blooded animals have arisen from one living filament, which the first great cause endowed with animality, with the power of acquiring new parts, attended by new propensities, directed by irritations, sensations, volitions, and associations; and thus possessing the faculty of continuing to improve by its own inherent activity, and of delivering down those improvements by generation to its posterity, world without end! If this sounds Lamarckian, that's because it was. Jean-Baptiste Lamarck believed that creatures could inherit characteristics acquired by their ancestors - that if, say, a blacksmith acquired huge muscular arms by virtue of working for years at his forge, then his children would inherit similar arms, without having to do all that hard work. Insofar as Erasmus envisaged a mechanism for heredity, it was much like Lamarck's. That did not prevent him having some important insights, not all of them original. In particular, he saw humans as superior descendants of animals, not as a separate form of creation. His grandson felt the same, which is why he called his later book on human evolution The Descent of Man. All very proper and scientific. But Ridcully is right. `Ascent' would have been better public relations.
Charles certainly read Zoonomia, during the holidays after his first year at Edinburgh University. He even wrote the word on the opening page of his `B Notebook', the origin of Origin. So his grandfather's views must have influenced him, but probably only by affirming the possibility of species change[47]. The big difference was that from the very beginning, Charles was looking for a mechanism. He didn't want to point out that species could change - he wanted to know bow they changed. And it is this that distinguishes him from nearly all of the competition.
The most serious competitor we have mentioned already: Wallace. Darwin acknowledges their joint discovery in the second paragraph of the introduction to Origin. But Darwin wrote an influential and controversial book, whereas Wallace wrote one short paper in a technical journal. Darwin took the theory much further, assembled much more evidence, and paid more attention to possible objections.
He prefaced Origin with `An Historical Sketch' of views of the origin of species, and in particular their mutability. A footnote mentions a remarkable statement in Aristotle, who asked why the various parts of the body fit together, so that, for example, the upper and lower teeth meet tidily, instead of grinding against each other. The ancient Greek philosopher anticipated natural selection: Wheresoever, therefore, all things together (that is all the parts of one whole) happened like as if they were made for the sake of something, these were preserved, having been appropriately constituted by an internal spontaneity; and whatsoever things were not thus constituted, perished, and still perish.
47
What would have happened - if Darwin had gone back in time and killed his own grandfather?