They hear the traction engine before they see it. They are in the kitchen finishing breakfast when its mighty throb vibrates through the house. Tom is out of his chair in an instant, running towards the door, bubbling with excitement, but Gwen cautions him as she rises from the table. Helping him on with his coat and wellies, she warns of the intrinsic dangers of the machinery visiting the farm that day.

Jack drains the last of his tea and takes his plate to the sink, thanking Muriel, who is already in the midst of washing up. He has never seen a threshing machine before and is unsure what to expect, but he is aware that today is an important day and Gwen has been looking forward to it. They had spent the previous afternoon removing the thatch from the towering ricks, with Gwen studying the sky, anxiously looking for signs of rain. But it has held dry and pale autumn sunshine now bathes the butter-coloured stacks of straw standing in the rickyard.

The three of them leave through the back door and hurry down the garden path as an enormous wooden monster rolls past them up the yard, pulled by the steam engine. To Jack it vaguely resembles a ship on wheels. A circular drum protrudes from the flat deck above them like a squat funnel, while its hull bears wheels connected by belts. Behind it comes another piece of equipment, which Gwen identifies as the baler.

They follow the machinery up into the rickyard and when it finally comes to a stop, a team of men clamber down – two from the engine, while five others scurry down the sides of the thresher like rats off a ship. Gwen greets each in turn, familiar faces all of them, her smile broad and welcoming.

Tom races forward to study the engine. Resplendent in bottle green it gleams in the sunlight. Gwen shouts a word of caution and Jack jogs to catch him up, hoisting him up onto his shoulders so he can better see its incessant pistons and the flickering needles in its gauges.

‘Tom, I want you to go inside now to Muriel. I need you to stay out of the way today, the thresher and engine are very dangerous for little boys,’ Gwen calls.

‘But I want to stay and watch.’

‘No, Tom. Daddy and I will be busy helping, we can’t keep an eye on you at the same time. I’ll ask Muriel to bring you out in a bit and you can stay and watch then. You’ll soon get bored of it – I can guarantee that.’

‘I won’t.’