As bikes got cheaper, the craze came to an end, to the relief of scandalised Victorians who worried that cycling made women infertile, caused disease and loosened their morals.

In recent years another technology has expanded people’s social circles and dramatically broadened their romantic opportunities: online dating. Like bicycles, apps and websites bring together people who might otherwise not have met, but on a far larger scale. In America more than a third of marriages now start with a digital match-up. Online dating is fast catching up with “friend of a friend” introductions as the most popular way to meet people of the opposite sex. Among same-sex relationships, 70% now start online.

Evidence suggests that marriages in America between people who meet online are likely to be happier and last longer. Online dating also seems to be boosting interracial marriages by overcoming social divisions. Dating apps have completed what the bicycle began. Both technologies are, you might say, revolutionary.