Darwin invited Sofia and me to crew for a balloon trip on Saturday morning. 'Crewing' means helping to transport, inflate and launch the balloon, before following it round the country in a car for an hour, meeting it in a field somewhere and packing it all away again.

We started in Botley park, south Oxford, at 6 o'clock on a chilly end-of-summer morning. It takes ten minutes to unfurl the envelope (the big fabric part of the balloon) on the ground, taking care not to rip the fragile material; another ten to inflate it with cold air from a powerful fan running off a diesel generator; five more to heat up the air, climb in and take off. Here it is, from start to finish, in ten photos.

In other news, Alice had her first birthday on Friday. Balloons, kisses, cakes, presents, friends - she was very happy all day. Sofia and I lost to Geoff and Meg in the finals of the annual Lower Windrush tennis club mixed doubles tournament. Samir says we weren't aggressive enough at the net; I think he's right.