Age of Invention: A Breath of Fresh Air

Welcome to my weekly newsletter, Age of Invention, on the causes of the British Industrial Revolution and the history of innovation. You can subscribe here:

One of the most worrying diseases of the mid-eighteenth century was typhus. We now know that it is spread by lice or fleas, but at the time, like so many other diseases, it was thought to be caused by noxious air — “malaria”, for example, literally means “bad air”. This was not a silly theory. It was based on empirical observation, which perhaps explains why the belief in such noxious miasmas persisted for so long — well into the late nineteenth century, if not the early twentieth, before finally being ousted by germ theory. Our ancestors were not stupid, no matter how strange their beliefs might appear in hindsight. (Also take alchemy, or the belief that some animals spontaneously generated.)

Typhus fit the miasma theory especially well because it frequently appeared in confined spaces, like ships’ holds, prisons, mines, workhouses, and hospitals. The disease was thus often called “gaol fever”, or “hospital fever”. And there was the fact that at least one of the solutions designed to combat miasmas, the ventilator, actually seemed to work. This ventilator was not the kind that is in such high demand right now, used to help feed oxygen into patients’ lungs, but instead a machine used to get the air flowing in and out of confined spaces — like a 1740s air-conditioning unit.

At first glance, removing the stale air from a space shouldn’t do anything against typhus. But mortality declined drastically in the prisons and ships to which the ventilator was introduced. It halved the number of deaths per year in Newgate prison, where the bellows-like machinery was powered by a windmill, and the inmates of the Savoy prison fared even better. On ships, too, mortality declined among mariners, passengers, soldiers, and especially among the group that suffered most from long voyages across the eighteenth-century Atlantic: slaves.

But it’s not clear exactly why. After all, the ventilator did not kill the typhus-ridden lice or fleas. I have a few theories as to what must have been going on. Perhaps, by improving the supply of oxygen to confined spaces, people’s bodies were simply better served to deal with all manner of diseases. Surgeons aboard slave ships sometimes noted that, without proper ventilation, many slaves would simply die in the night of suffocation. Or perhaps the ventilator’s effectiveness had something to do with its drying effect. The machine was used to prevent grain stores from becoming humid, thus staving off damp-loving weevils. The ventilators might thus have staved off typhus through a similar means: although I’m not so certain about body lice, humid conditions are preferred by fleas. Regardless of the real reasons, the ventilators worked, and even when they did not reduce mortality, they made confined spaces more bearable for those who had to endure them. Ship captains reported that they did not even have to force their sailors to pump the ventilator’s bellows, because they liked the cool air so much. Ventilators were soon installed in the House of Commons, and in many of London’s theatres.

But what interests me most about the ventilator was its inventor, the Anglican clergyman and amateur scientist Stephen Hales. Hales had spent much of his scientific career investigating how sap flows through plants and how blood circulates in animals, as well as how both fluids interact with the air. But it was not until his sixties that he finally applied his scientific knowledge to preventing typhus (even if the science would later turn out to be wrong). Like so many other scientists, he had largely been content to advance our understanding of nature, but not our use of it. His own brother had even probably died from typhus, while in prison for debt, but it was decades before Hales applied himself to inventing the ventilator.

Once Hales had caught the invention bug, however, he could not help but spread it further. He came to believe that more scientists should be seeking to apply their knowledge, both for the good of humankind, and to prove that the study of science was “not a mere trifling amusement”. He became known for offering innovative tips and tricks — what today we might call life hacks — to all and sundry. He used his understanding of chemistry to advise ladies on how best to prevent limescale in their tea kettles, and applied his knowledge of pneumatics when he advised them to place a teacup in their pies, upside-down, to prevent the juices boiling over. Just before he died, in his mid-80s, he was even seen painting the tops of his local footpath posts white, in order to prevent people injuring themselves on them at night. Yet Hales’s most lasting legacy was to help create an institution that would continue to spread innovation further. Although he was a fellow of the Royal Society, Britain’s premier scientific organisation, he saw the need for an organisation that would systematically promote knowledge’s application. Thus, in 1754, in a London coffeehouse called Rawthmell’s, Hales and a few others helped found the Society for the Encouragement of Arts, Manufactures and Commerce — a society for the improvement of anything and everything. It still exists today, usually known as the Royal Society of Arts (and, incidentally, it’s the subject of my first book - the hardback available at 25% off and free shipping with the code AAM20).

Over the following weeks, I’ll share a bit more about it.

Until next week,


P.S. I realise I’ve been posting less frequently of late. I’ve been writing elsewhere. Here’s a piece I wrote last week on systems for promoting innovation, and how they can be used to combat the pandemic (there’s a bit of history in there, too).