One of the secrets of a good book is a curious author. Consider this from Matt Ridley:

“I walk a lot in London, and a few months ago I set myself a goal: somewhere in the vast city, while walking down a street, to catch the smell of sewage. I have yet to achieve this goal. Close to ten millions defecations occur in London every day, presumably, for most people it is daily occurrence. I hazard that I am rarely more than 100 feet from somebody actively at work on this task … Yet you never smell it. Why not? This is a new phenomenon, an innovation”.


How many people ever think about such things? The fact that a city as big as London doesn’t smell of sewage is now taken for granted, in spite of the fact the opposite was true for quite a long time. This is “one of the finest achievements of our civilization”, writes Ridley, and he is not joking.


One of the key elements behind the ingredients was the S-bend in the pipe beneath every toilet, which traps water so as to prevent the smell to come back up. Before it, “flush toilets were expensive and unreliable and they had the huge disadvantage that they took away the sewage but not its smell”. The S-bend, “one of those things that could have been invented at almost any time and by almost anybody”, was actually the product of a “fine mathematical mind at the height of the Enlightenment”, Alexander Cummings.


It may sound strange to recommend a book on innovation because he neatly presents, in only a few pages, the history of the water closet and the modern sewage network – but I think this is not a minor merit of Ridley’s book.


Besides commending Matt’s walking habits, I think it is worth stressing again the logic of the book: “innovation” consists not only of things that are big, visible, and breath-taking (pardon the pun). Innovation is a pervasive phenomenon in a modern economy, all the more relevant in the daily undertakings of life, that are improved, little by little, with most of us not noticing it and happily taking for granted a better status quo than our forerunners ever dreamt possible.


Read the earlier posts in this series here, here, and here.