Girls in crisp cotton pinafores, boys with white collars and waistcoats, the children leave their respective cloakrooms. They reach the second floor of the light, airy building by separate staircases to line up quietly outside the classroom door.
Teacher Helen Duncan has brought her P6 class from Mayfield primary school in Saltcoats, Ayrshire, to Scotland Street school in Glasgow. Today they have travelled 30 miles by bus and 100 years back in time to do their morning's work in a faithful reconstruction of a Victorian classroom.
In 1906 Scotland Street school first opened its elegant gates to the children of Glasgow's working class Tradeston and Kingston districts. The tenements are now demolished but the school, designed by Charles Rennie Mackintosh, is a museum of education. It is visited by the public, by classes from all over the country, and is a place of pilgrimage for Mackintosh enthusiasts worldwide.
In the role of redoubtable Victorian schoolmistress, actress Jennifer Stevenson greets P6 and tells them to call her ma'am. "When you talk to me, the boys salute and the girls bend the knee. Good morning, boys and girls."
"Good morning, ma'am," chants the class in unison, boys saluting and girls bobbing a curtsey. "She's strict," somebody whispers. "Silence!"
snaps Miss Stevenson. Instantly the children are seen and not heard.
The Victorian classroom, with old double desks in tiers, is spartan. A map of the world shows in pink the empire on which the sun never set. The children are told where to sit; arms folded, backs straight as they listen to the Bible reading. Next to godliness comes cleanliness. Hands are inspected. Have clean hands and trimmed nails or you will not find employment. Write neatly, speak properly, be punctual and you will find employment. A recurring theme is the imperative of finding work. The significance of this is not lost on the pupils who have been studying the Victorians. Now they experience first-hand the rigours of the education system.
There are 24 children, but this room once accommodated up to 60. With no group teaching, it was a case of sink or swim. So it's in at the deep end with arithmetic, chanting the tables followed by oral questions and written problems. Soon all eyes are down and slate pencils scraping busily.
Helen Duncan, the usual teacher, comments: "We had a Victorian day at school, and we dressed for the occasion. However, our school is new and semi open-plan, so coming to an early 20th-century one which held 1,500 pupils aged five to 13 is an eye-opener. Living the experience in a genuine old-fashioned classroom with schoolmarm, strict Miss Stevenson, is something else."
Next, inkwells are filled. Pens and blotting paper are given out.
"Tramline" paper, with dark and feint lines, is distributed, and the alphabet in cursive writing demonstrated.
"There is no left-handed writing permitted in any Scottish school, so if you are left-handed, keep your left hand out of sight or it will be strapped behind you."
A different kind of strap is to be demonstrated later. But first Miss Stevenson blows a shrill whistle and launches into drill. "Stand, feet apart and bend and stretch... and rest and sit."
After a benediction Miss Stevenson, to the obvious relief of some pupils, comes out of role to laugh and tell of dipping girls' pigtails into inkwells and the dire consequence of this. It is the tawse, a leather strap. As it crashes down on a stool a few children wince or cry out. The session ends with the class singing lustily.
Packed lunches can be eaten in the cookery demonstration room. With the fully-equipped black range, this long kitchen looks as if the Glasgow girls of the 1920s could walk out of the photographs on the wall and continue baking where they left off. The museum has Second World War and 1950s60s classrooms, displays, interactive activities, listening posts and exhibitions.
But the glory is the Charles Rennie Mackintosh building itself and the evocative way in which the atmosphere of schools past is authentically captured.
www.glasgowmuseums.com; tel: 0141 565 41123. Open Mon-Thurs and Sat 10am-5pm; Fri and Sun 11am-5pm. Re-enactments: P5-P7 pound;75; self-led free. Toys: P1-2 pound;25. Wee Architects, Wee Builders, pre-5s: pound;10; P1, pound;25