Mathematical Bridge

The most recognised bridge on The Backs in Cambridge; The Queens' College Mathematical Bridge is famed as an example of a perfect bridge – at least in engineering terms.

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 Bridge of Sighs is one of Cambridge's most recognisable and beautiful landmarks and is an integral part of life at St John's. Designed by architect Henry Hutchinson in the Victorian Gothic style, it remains to this day the only covered bridge to cross the River Cam.

The construction of mathematical bridges is based on an underlying geometrical pattern. The term is generally applied to wooden bridges with criss-crossing structural elements in their main supporting frames as can be seen in the small foot bridge at Queens' College, Cambridge.