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On Jean Valjean’s carriage, technological progress and interchangeable parts

Jean Valjean – in a desperate hurry to save an innocent man from being condemned – has stopped to rest his horse and discovered that his carriage has a broken wheel:

This excellent beast had covered twelve and a half miles in two hours and had not a drop of sweat on its rump.

“Can you repair the wheel immediately?”

“Yes, monsieur.”

“When will I be able to set off again?”



“It’ll take a full day’s work. Is monsieur in a hurry?”

“A very great hurry. I must be on my way in no more than an hour.”

“Impossible, monsieur.”

“I’ll pay you anything you like.”


“Well, in two hours, then.”

“Today’s impossible. Two spokes and a hub need to be remade. Monsieur will not be able to set off again before tomorrow.”

“Haven’t you got a wheel you could sell me? Then I could set off again at once.”

“A spare wheel?”


“I haven’t got a ready-made wheel to fit your gig. Wheels go in matching pairs. Wheels aren’t paired at random.”

“In that case sell me a pair of wheels.”

“All wheels don’t fit all axles, monsieur.”

“Try, at least.”

“It’s no good, monsieur. I’ve nothing but cart-wheels to sell. This is just a small place.”

Victor Hugo – Les Miserables

Some thoughts:

  • In 1823 (when the novel is set), six miles an hour was a fast speed for a long cross-country journey – Valjean has gone to serious effort and expense to get the best horse and cart available for the job (a return trip of fifty miles)
  • In the absence of mass-produced interchangeable parts, replacing any wheel is a big job and huge expense – Valjean will have to wait a full day, whereas you likely carry a spare wheel appropriate for your own and almost any other car in your boot/trunk.
  • In 1815, transportation is a scarce good: for the right price a modern Jean Valjean would easily be able to hire someone to help him make his journey (almost any adult could drive him), or could buy a replacement vehicle almost anywhere.
  • All of these changes – faster travel on better roads with more reliable and more easily repaired vehicles – are products of interactions across a wider system, not just of better techniques in a single field or the skills of individual people.

In terms of the speed we travel, the distance we cover, and the comfort and ease we do it, it’s easy to forget how far we’ve come.

I'd love to hear your thoughts and recommended resources...