I'm watching a building site, and in particular a 360 excavator with a long arm. This is a yellow JCB vehicle on two large caterpillar tracks with a cab that can rotate all the way around, and a big scoop on an articulated arm at the front. The arm is curiously prehensile. It's filling a truck with rubble, and the excavator uses the back, curved side of the scoop to smooth down the heap before the truck drives off. Then the JCB has to move down a steep slope to pick up a bit more, so it steadies itself with the back of the scoop again, holding its arm out infront and bracing against the ground.

The portacabins - the temporary site headquarters - in the background are four deep and two high, and the whole block lifted two stories above the ground with girders. It was erected in a day or two, with a couple more days to lay quick foundations. It makes me laugh to see people using their specialities to make their jobs easier. I heard the other day that SMS was a hack by Ericsson engineers so they could communicate while they were working on the infrastructure without interrupting voice calls. The first thing the Mozilla opensource project did was write a web-based bugtracking system.

The light touch of experts. The unconscious ease with which they wield these extra limbs. It's beautiful. Out of respect I have to refer to the JCB and its driver as a single unit, man-machine. My sister the civil engineer tells me that these same excavators can turn on the spot by pivoting on the shovel, and one with claws on the end of the arm can pick up a glass milkbottle without breaking it.