The day started off as forecast, with rain. So I decided to fit the new mains sockets to take the router and external backup hard drive. By the time I had done this the sun was peeking out and so we thought that we would go and do some Geocaching away from Oxford town centre and towards Iffley Lock and the nature reserve.
The first Cache we did was at the lock, nearby there is a wooden bridge called ‘The Mathematical Bridge’ this is the description from the Geocache:-
The main members of each rib are set at tangents to the circle describing the underside arch of the bridge. An engineering analysis will show that, in the arch itself, each member is in compression with little or no bending moment, an ideal application for wood as a structural material. Where the main members cross, the wood joint is designed to transmit the compressive stress from one member to the next, with a bolt serving to hold the joint together laterally, rather than carrying any stress. There are also radial members which both support the top rail and lock all the overlapping tangents into a rigid structure, by creating triangles out of quadrilaterals.
Mathematical Bridge
While we were at the lock we thought that we would have a look at St. Mary the virgin church, it is the best surviving example of a Norman church in the country (so the notice said).
Iffley Norman Church
Note the clear blue sky.
We spent the rest of the afternoon trying to sort out a multi cache, which we eventually found after much going around in circles.
Statistics so far:-
660.80 Miles, 495 Locks, 47 Swing Bridges, 27 Lift Bridges, 6 Tunnels.
