Here’s how you hoist up the John B sail

This lovely thing is a Meissner Classic winch and is intended for hoisting and releasing a yacht's sails. It withstands enormous forces as becomes apparent if you incautiously unhook the rope from that beautifully shaped securing device and leave your fingers in the way. Engage a crank in the top and the mechanical advantage allows a human to haul with the power of ten. A ratchet prevents the wind-filled sail from biting back. That's all there is, really. Yet those on my brother's yacht cost £700 each. A matching pair would look good on your mantelshelf (as they say in the North).

Car door needs protecting from physics

Remember the law of levers. The longer the lever the greater the force that can be applied. My car door is just one example of why you should always stay on the right side of this particular law. When open, the door's edge extends some 1.5 m away from the car body. Far enough for the weight of the door itself (no lightweight) to deliver plenty of destructive force at the attachment point to the car. The idea of a driver leaning on the top of it while chatting to someone in the car park doesn't bear thinking about. Which is why the hinge (one of two) in the centre of the photo is extremely substantial. I'd be overdoing things if I called the hinge pretty but it has its own rugged charm. Rugged and reassuring. I glance at it with pleasure every time I get into the car.

TECHNO-ART Which painter made best use of technology as a subject in an acknowledged masterpiece? Answer: Turner in "Rain Steam and Speed". Closely followed by his poignant canvas of The Fighting Temeraire being towed to the breaker's yard by a steam tug.