Down a mineshaft or why historians (must) become polymaths.

A few weeks ago I wrote a somewhat tongue in cheek post about The Ideal Historian of Science. I say somewhat because in reality a historian (and not just a historian of science), who is worth his or her salt, has to be a widely eclectic polymath prepared to mug up on a new discipline or field of human endeavour whenever and wherever the subject he is studying or researching demands it of him or her and believe you me such demands occur much more often than the non-historian would imagine.

I have, for example, over the years many varied reasons as to why I had to confront the subject of mining, mostly, in the early modern period. I have been led there by investigations into alchemy, geology, mineralogy, early European algebra, economics, astronomical instrument manufacture and physics amongst others. Also by people as diverse as Georg Agricola (mineralogist, *15^th C), Adam Ries (reckoning master, *15^th C), John Dee (alchemist, *16^th C), Evangelista Torricelli (physicist, *17^th C) and Alexander von Humboldt (polymath, *18^th C). In what follows I will sketch one simple example from the history of science that if investigated more deeply leads unavoidably to a confrontation with the history of mining.

My example starts with a historical anecdote that is often used in school physics lessons. In 1648 the French polymath Blaise Pascal sent his brother in law, Périer, up the Puy de Dôme, a volcano in the Massif Central, carrying a primitive barometer. This experiment demonstrated that the level of the barometer’s column of mercury varied according to the altitude thus ‘proving’ that the atmosphere had weight that lessened the higher one climbed above the earth’s surface. This experiment provided a necessary building brick in the theory that the earth’s atmosphere doesn’t get blown away if the earth is moving because it is held in place by the force of gravity. Thus disposing of one of the most serious objections to heliocentricity. This proof had to wait, of course, for Newton to develop the theory of universal gravity, which still lay a few years in the future.

With his barometrical experiments Pascal was confirming and extending the results obtained earlier in the same century by the Italian physicist Evangelista Torricelli who is usually credited with having invented the barometer. Now at this point in the story a good historian will ask, what led Torricelli to invent the barometer? It’s here that we, so to speak, fall down a mineshaft for the first time. Torricelli was trying to find out why an air pump could only pump water to a height of approximately ten metres. The answer as we now know is because atmospheric pressure is only strong enough to support a ten-metre column of water. This was Torricelli’s great discovery. But why was Torricelli investigating this problem at all? The answer was mining. The Renaissance saw a vast increase in mining particularly in Middle Europe, which increased the necessity of pumping water out of mineshafts leading to attempts to improve the quality and efficiency of air pumps, thus Torricelli’s investigations. The question that now confronts our historian is why the increase in mining but having shown how a question about the history of the discovery of atmospheric pressure leads to mining I shall leave that question for another time and head in the other direction down times arrow.

As I’ve already indicated Torricelli’s and Pascal’s barometric experiments played an important role in establishing the heliocentric theory in cosmology but that was by no means their only scientific of technological consequence. These experiments, as is well known, also demonstrated the existence of the vacuum something that had been disputed since antiquity. In fact Pascal’s confirmation of the existence of the vacuum led to a dispute with Descartes, whose mechanical philosophy had no place for the existence of empty space. However other more open minded thinkers than Descartes seized upon this nothing and used it to further the progress of science.

Otto von Guericke invented the vacuum pump, which in the hands of the Roberts Boyle and Hooke, amongst others, proved a source for an apparently endless series of experiments that would eventually lead to the understanding of the function of respiration in animals as well as in plants and many other fascinating discoveries. However I wish to follow the vacuum in a different direction.

Leibnitz’s attempts to create a vacuum using explosions led his assistant Denis Papin to invent the first atmospheric steam engine. As an aside it should be noted that Papin worked on and improved Boyle’s vacuum pump. Papin’s steam engine never got beyond the model stage but in 1712 Thomas Newcomen either stole Papin’s idea or reinvented the atmospheric steam engine; it is not known whether he knew of Papin’s work or not. Newcomen’s engine was famously inefficient and it was first the Scottish engineer and inventor James Watt who succeeded in making the steam engine a viable proposition.

Now Watt’s work was not something that happened overnight but was a long and weary process that took many years and a great deal of financial investment. Although he was a successful instrument maker Watt could not produce the type of finance necessary to see his steam engine project to fruition so he needed a powerful financial backer. He found the support he needed in the person of the industrialist and member of the Lunar Society, a group dedicated to scientific research, Matthew Boulton. Now we have to ask why was Boulton prepared to invest vast amounts of money to allow Watt to perfect his steam engine? Boulton needed a more efficient source of power to pump the water out of his tin mines in Cornwall, which takes us back down that mineshaft.

Anybody doing contextual history will, no matter what the starting point of his or her investigations, eventually run up against one or other field of human endeavour about which he or she is more or less ignorant. When this happens our intrepid historian has one of two choices he or she can either stop his or her investigations at that point and not answer the obvious questions that have popped up or he or she can buckle down and acquire a working knowledge of a new field thus increasing his or hers status as a polymath.