About
The bridge was designed in 1748 by William Etheridge (1709–76), and was built in 1749 by James Essex the Younger (1722–84). It has subsequently been repaired in 1866 and rebuilt to the same design in 1905.
The earliest discovered use of the term Mathematical Bridge in relation to the bridge at Queens’ was in A Guide through the University of Cambridge, of 1803, as a footnote to a description of the bridge on page 68: Usually known by the name of the Mathematical Bridge.
A different publication, Cantabrigia Depicta, by Harraden & Sons, made a similar comment in 1809. Some care is required in interpretation, as the phrase Mathematical Bridge was also being used in the same period to describe the similar bridge at Garret Hostel Lane and either bridge might have been confused with the other.
The bridge is 50 feet 8 inches (15·44 metres) long. The angle between two adjacent radials (except the ones on the abutments) is one 32nd of a revolution. The arch is composed of tangents to a circle of radius 32 feet.
The Legend of the Mathematical Bridge
According to the legend or anecdote, much favoured by Cambridge tour guides, the Mathematical Bridge was built by Newton from nothing else but wood. No nuts, no bolts, just what wood can make and bear. The legend says that Sir Isaac Newton built the bridge to illustrate the principles and properties of force and gravity.
Then, after Newton’s death, the students / fellows of Cambridge University, who were curious to learn about the exquisite structure of the clever wooden bridge, disassembled the Mathematical Bridge, but failed to re-assemble it properly. As they could not put together the intelligent bridge again, they had to use iron pins, nuts and bolts to make the bridge functioning again.
It is a lovely story, and a wishful credit to the mathematical genius of Newton, but it is nothing more than a colourful anecdote. The truth is that such a bridge could not have been built from wood only, taking its size, weight and structure into consideration.
Not to mention the fact that Newton was already dead in 1727, by the time the bridge was actually built in 1749 by James Essex the Younger.
Know Before You Go
You can get a great view from the nearby Silver Street Bridge
