The famous wooden Mathematical Bridge at Queens’ College is a highlight of the Cam punt tour. It bridges the river to connect the two parts of Queens’. The story goes something like this: “It was designed by Sir Isaac Newton – and put together without any nails or bolts. When they had to take it down to repair it they couldn’t figure out how to put it back together again, and that’s why the bridge you see now is bolted together.”
Now, the Mathematical Bridge actually has nothing to do with Newton, and has certainly always been held together by more than just the gravity-defying Power of Maths (the original was built in 1749). But the story of a wooden bridge with no nails actually has a much longer pedigree.
Plutarch tells us in his Life of Numa (IX.3-4) that the first bridge ever built in Rome (known as the Pons Sublicius, or bridge of piles, presumably because of the way it was constructed) was also a wooden bridge, with no iron nails. “The Romans held the demolition of the wooden bridge to be not only unlawful, but actually sacrilegious. It is also said that it was built entirely without iron and fastened together with wooden pins in obedience to an oracle.” Whenever the bridge was destroyed by the Tiber flooding or other disasters (always a bad omen) it would be piously rebuilt in the same form.
The similarities between the two stories are pretty striking. Both try to explain the anomaly of a lone wooden bridge on a river bridged by stone – an antique curiosity in both cases. Just as the Mathematical Bridge legend links its creation to a sage of the past (Newton), the Pons Sublicius is connected with Rome’s farsighted second king, Numa Pompilius (or his grandson, Ancus Marcius). The continuity of form is emphasised – the Mathematical Bridge has also been substantially rebuilt twice but maintained the same design. Both are linked with supernatural knowledge – whether that’s oracular or mathematical!
Coincidence? A quick google has revealed the existence of other wooden bridges without nails, the Kintai Bridge in Japan, or example. Or is it possible that the Queens’ legend was originally influenced by scholars’ knowledge of the Pons Sublicius (which is the bridge destroyed in the famous story of Horatius Cocles)?