Old Walton Bridge

Depicted in a 1754 painting by Antonio Canaletto.  The structure of the bridge intrigued me (click it bigger to see what I'm referring to).  Here's what I found out:

In 1747 Samuel Dicker, local landowner and later MP for Plymouth, obtained permission to build a bridge at Walton. It was designed by William Etheridge and built by White of Weybridge to consist of "timbers tangent to a circle of 100 feet diameter" and was built so that a single timber could be extracted and repaired without disturbing the rest of the bridge. Old Walton Bridge was completed in August 1750 and acquired some fame, meriting an article in the Gentleman's Magazine, a report in Daniel Defoe's Tour in 1753 and a painting by Canaletto in 1754... The timber structure stood until 1783. 

Via Miss Folly.

Addendum: A hat tip to Pete, who searched the 'net and found an example of this type of bridge - the "Wooden Bridge" in Cambridge ("The bridge was built in 1749 by James Essex the Younger (1722-1784) to the design of William Etheridge (1709-1776). It has subsequently been rebuilt to the same design in 1866 and 1905.")

Second addendum, courtesy of an anon:

The bridge in Cambridge is called Queens' Bridge, because it connects the two parts of Queens' College separated by the River Cam. It is even more commonly called 'The Mathematical Bridge', and is popularly (but wrongly) supposed to be built entirely of wood.

(Queens' College was founded by two queens, one after the other, which is why the apostrophe goes after the 's' and not before it.)