I walked back to the car. There was a tractor working the field over the hedge. That’s the second photo. I looked at the map. I drove on, and crossed the A421 where The Lone Tree pub used to be, and headed roughly North. I crossed the A422, stopped once to check the map, and drove onwards to the edge of the county, to see what was there.

I found red kites, fourteen of them, drifting and calling above the woods that lay either side of the road.

Less than a mile and a half across the fields was Silverstone racing circuit. I could hear somebody hooning round the track, their exhaust howling.

The border with Northants runs along the North edge of these woods. Shrine’s Wood is on the West of the road, and Lovel Wood is on the East. I was on a minor main road, the A413.

The sun was getting low. While the kite’s wings caught the light as they banked, I was in shadow. It was time to go. The car had been beeping at me to say my fuel was low, so I headed back to Buckingham and filled up.

I was now heading East along the A422, but before I crossed my earlier path at the Lone Tree junction, I pulled off to have a look at the old Thornborough bridge.

This bridge is the only medieval bridge left in the county and dates from the end of the fourteenth century. There are three triangular refuges on the South side, and I could see some dull red paint on the corners.

It just looked like ordinary paint until I took my first picture, with a touch of fill in flash. The paint was retroreflective, and bounced the flash light directly back into the lens. you can see this in the first bridge photo. This is the middle refuge of the three.

Despite this safety feature, there were deep grooves where Westbound vehicles had hit the bridge sides; until 1974 the main road crossed the bridge.

I looked at the corners that faced the other way. These all had patches of white paint, for vehicles coming in the opposite direction.

You can just see the red patch in the middle refuge of the bridge in the photo below, but without the flash it's dull. There's no bright light to reflect back towards the lens, in the same way as the beam from a headlight reflects back to a driver's eyes.

In 1960, perhaps later, (I've been looking at old OS maps) the road between Buckingham and Bletchley was still a minor one and labelled as the B4034. On old maps it’s obvious that the route is made up of several very minor roads joined together at what used to be T-junctions to form sharp bends, like the old Bottledump Corner. The line of the road has been smoothed out over the years, and Bottledump is now a roundabout, the first one on the Milton Keynes grid system when you come from Buckingham.

That’s it for this week.