The youngsters, from schools on both sides of the Border, become Celts and Romans for the day in Luguvalium (Roman Carlisle). I joined a class of seven to nine-year-olds from Trinity Junior C of E School in Keswick. The school’s deputy head, Aileen Scorer, defying Roman custom in which women knew their place, has donned a Roman toga to become Julia Augusta, “governess” of Luguvalium. The children choose their own costumes. The boys opt for the grey woollen Celtic dress and the tunics of the craftsmen. Three of the girls decide on togas; the rest struggle into long tube dresses.

Julia Augusta tells the assembled townsfolk that some people have been so disturbed by rumours of a threatened Pictish invasion that they have taken to burying their belongings for safe keeping, showing a lamentable lack of faith in the Roman legion’s ability to defend Luguvalium.

“Who will help me find these traitors?” she demands. Every hand shoots up all anxious to begin the “Roman Detective” role-play devised by Grant Ogilvie, education officer at Tullie House. The role-play, he maintains, aims to give children “a perception of life which is remote yet accessible”.

Five of the “buried” sacks are produced and distributed. The youngsters’ task is to identify, from the contents, the sort of person to whom each sack belonged. “It’s a lady; we’ve found some jewellery,” I’m told by one group. They have to rethink this later when they find that men also wore jewellery. “I know what this is, it’s one of those pencil things,” declares a small girl excitedly. The group later identifies the “pencil thing” as a stylus when they see one on display.

One of the sacks, another group decides, belongs to a Roman soldier. “Not one of my soldiers, surely,” says a suitably-shocked “governess”. “Yes”. “We’ve found some chain mail, dice, and a letter addressed to ‘Marcus’ from his mum,” they tell her. (The wooden letter tablet is based on genuine Roman tablets at nearby Vindolanda Roman Museum). The children are helped with the translation by a Latin vocabulary list supplied with the sack. Marcus is berated by his mum for not having written for ages. Despite this neglect, she says, she is sending him a pair of underpants and two pairs of socks. Marcus and his nagging mum immediately become real people to the children.

They all scamper off to see what else in their sacks is identifiable from the displays. They come upon a Roman saddle on a wooden horse the sort used by recruits to practise vaulting on to their horses. Celts, merchants, high-born ladies and toga-clad officials all temporarily forget their roles to clamber aboard.

Julia Augusta, reverting briefly to Aileen Scorer, says she’s not so concerned with the children getting the “right” answer about the owners of the sacks as getting their hands on the artefacts and managing to match them up with objects in the museum. “It’s making them think,” she says. And some of them show considerable ability in deductive reasoning.

“We think our sack belongs to a Celtic farmer,” one group tells me. “He’s got an order to deliver some sour wine to the legion.” (Again worked out with the help of a vocabulary sheet.) They’re a bit puzzled about some of the other objects, including a weighing device which they have recognised as similar to the steel yard on display. “Would a farmer have those?” they’re asked. One bright lad suggests that he’s a Roman soldier-turned-farmer, but eventually they reach the conclusion that he’s a Roman merchant trading with the local farmers.

And so it goes on a “rich Roman lady” is identified by a filigree bracelet and a spinning whorl. There are even a child’s possessions in one of the sacks a tiny toy mouse, an elephant, a doll and a small shoe. Suddenly Carlisle really is Roman Luguvalium for these children and the remote has become happily accessible.

Tullie House Museum, Castle Street, Carlisle CA3 8TP is open 10am to 5pm Monday to Saturday and 12 to 5pm on Sunday. Adults Pounds 3.30, children and concs Pounds 2.00, family ticket Pounds 10. Education rates available. Tel: 0228 34781