The children are unusually quiet as they watch and wait for the waterwheel to start turning at the historic Mill of Benholm.
Then comes the rhythmic churning, as the sluice opens and the water descends along a trough from the mill pond and cascades on to the waterwheel, urging it into action.
This is the only surviving water-powered traditional meal mill in Aberdeenshire, restored to working order in the heart of an ancient woodland. There's a museum and a woodland classroom here for schools like Middleton Park, which has come to visit from Aberdeen about half an hour north.
This visitor centre is run by a charitable trust, which works with Aberdeenshire Council to give work experience and training in catering, gardening and maintenance to fourteen adults with special needs.
It's also an incredible learning resource and this morning the Primary 5 pupils are exploring the Mill of Benholm and surrounding woods, finding out for themselves how the mill produced oatmeal for this community for centuries.
The children have come here with Aberdeen's Reading Bus, a project launched seven years ago to improve literacy in the city. A new initiative for schools is focusing on science and functional literacy, and today children are investigating "water and renewable energy".
"We've just finished a project on the Titanic, and within that we looked at floating and sinking and the properties of water. So this has led on nicely from that into the energy side of things," says P5 teacher Lorna Shipley, who is the school's science coordinator.
It's a major project for the children and will culminate in a visit to the Hutton Institute's Virtual Landscape Theatre in Aberdeen to see how water turbines work in the west coast of Scotland by viewing them in 3D.
"Today we're learning how the mill works and about the use of water as a power source. We had a visit from two storytellers from the Reading Bus and they gave us a launch off with a story about the mill and about the power of the water," Miss Shipley says. "We have also looked at the old mills nearer our school and we'll do more of that when we go back."
For the moment, the children are concentrating on the landscape of Benholm Mill, walking the route of the Benholm Burn and watching classmate Jamie Ferguson open the sluice to get the waterwheel working. "Turning it clockwise makes it faster and anti-clockwise makes it slower," says Jamie, 9.
Their guide today is Mike Burleigh, project manager at Benholm and by good fortune a retired primary teacher. His tour of the woodland and mill museum is carefully pitched to suit the children's topic and level of ability.
The children take turns to pick up a laminated card he has prepared at each stopping point along their route to highlight the key learning points along their journey. Every so often, they stop to look at the wildlife along the way - moorhens on the mill pond and a search for tadpoles.
Their teacher has just completed a silver Primary Science Quality Mark for raising the profile of science within her school. Aberdeen was the first authority in Scotland to trial the PSQM Award and the school is now pursuing a gold award for its science work with pupils.
"I just love science and I have a science-based degree - it's my passion and it's what I love to do," Ms Shipley says.
The P5s seem totally absorbed as they walk through the woodland setting: "We've learned that there are gears in the watermill, that there are channels, rivers and a mill pond. It was really fun," says Shannen Guy.
WALKS AND WATERWHEELS
Ideally located on the coast road between Dundee and Aberdeen, the Mill of Benholm can accommodate visits from schools across the north-east of Scotland.
It is ideal for interdisciplinary learning and even on a dank winter's day like today, most learning can take place outside as children walk around the different locations.
Kirsty Aitken, the artist in residence with the Reading Bus, has been filming the children to track their work and create an online resource for teachers.
These children will do further experiments and create their own waterwheel back at school and work on functional writing in group work and peer assessment.
"It's very much a language-based observation we're looking at and hoping to inspire," Miss Aitken says.
There's another woodland walk on the other side of the burn for visitors and a woodland classroom has been built here at the suggestion of a local school.
"We have funding to put in a willow dome, the idea being if it's wet weather, we throw a parachute over the top of the willow dome and we have a classroom to retire from the rain," says project manager Mike Burleigh, a retired teacher who formerly worked in special education.
"Today, we started off looking at the head of water at the millpond and the fact that water exerts a pressure, then they did some investigations looking at water pressure," he adds.
"We then looked at the point at which the water is captured from the river and looked at how a change of direction in the water could take the water and draw it into the millpond, giving us a head of water. I was trying to get the children to understand that head of water is the equivalent of a battery - the equivalent of an element of power."