Marley's ghost appeared to Scrooge bound with "cash boxes, keys, padlocks, ledgers, deeds, and heavy purses wrought in steel". His fetters were the objects that preoccupied his working life. Had Scrooge been haunted by a spectral primary teacher, he would have seen someone encumbered by cardboard tubes, yogurt pots, envelope files, elastic bands and seed pods, uttering the mysterious cry, "My class might need them one of these days!".
Almost anything can help promote learning in a classroom where imagination is allowed free rein. Countless starting points cost no more than a second-class stamp, a phone call or a click on a mouse. Try a Google search on the words "free resources" and "teachers" or "schools", and you'll come up with more than 20,000 sites. So how to make sense of this embarrassment of riches?
Some of the best things are already on the internet. Accurate and suitable information is immensely valuable, and we can't carry it all in our heads.
Click on www.schoolzone.co.uk and you'll be guided to 40,000 educational sites that other teachers have approved. You can search by age group and subject, and play around with topics from astronomy to religion. If you're after something more specific for a numeracy lesson, make use of the generosity of the Association of Teachers of Mathematics' site at www.atm.org.ukfreestuff allows you to download probability games, cheerful animations about polygons and tangrams and starting points for dozens of investigations.
Human volunteers are often more precious than a shelf of books. On one unforgettable occasion I listened with a junior class as one girl's grandmother described her childhood in rural Jamaica 60 years earlier. She made history sing and dance.
In another school, set on a large council estate, tenants were canvassed about their musical skills. The result: assembly recitals played on everything from classical clarinet to folk guitar.
And who could resist an invitation from the bagel shop owner who proudly demonstrated his culinary methods to the school across the road and its teachers who contributed to his daily income?
Then there are physical objects. Be resourceful about searching them out. A Bermondsey teacher asked if she could look round a house that was being demolished and came away with a genuine Victorian "dolly tub" and scrubbing board. Banks, post offices and health centres are full of multiple copies of documents that allow children to combine role-play with a literacy lesson, filling in names and addresses, sorting items into alphabetical order and interviewing one another.
Supermarkets and street stalls have dozens of assets to give away just before closing time: plastic mushroom trays that turn into stackable display containers, coat hangers for a drama cupboard, multi-coloured plastic bags that can be shredded and woven into fashion accessories or bunting for the summer fete. And don't forget that nature - whether it's garden or wild country - produces an infinity of riches, from buds and rose-hips to sheep's wool and snail shells.
Sarah Richardson, an artist and teacher whose organisation Art Time inspires children to remarkable work, offers invaluable advice on the skills of creative blagging. "Explain to people in shops what you're trying to do. Even if they haven't their own children, they were once children themselves," she says.
A good letter from the class provides more real-life literacy practice and is more likely to produce results. "And at the end of your project, send a thank-you note with a photograph of the work you produced," she adds. "The goodwill then works two ways."
One teacher I know approached a famous Knightsbridge store just before Christmas and asked what they would be doing with their window display. In early January, her class had many lengths of beautiful textiles to work with.
Sometimes you don't even need to ask. There are organisations willing to bombard you with learning packs and discovery folders. But it's a good idea to be slightly sceptical - manufacturers of fizzy drinks and sweets send out materials on healthy eating with a morally furtive air - but you can pick up some items of value.
Groups working for animal welfare are especially concerned to get their message over. Cats Protection does an admirable booklet covering literacy, numeracy, citizenship and PHSE. Bears of the World pulls no punches in its portrayal of what adult humans do to the real-life version of their childhood teddies. It encourages respect and knowledge of some awesome species.
Health education groups take trouble to produce packs that help children enjoy what they learn. To you, Artie Beat may seem no more than a bright red cartoon heart with a big smile. To key stage 1 readers, he and his friends are the source of good-natured advice on what to eat and how to stay fit, wrapped up in comical quips and bold adventures - perhaps not the last word in literature, but carrying an important message.
Historical sites can be inspiring and inventive. The Hadrian's Wall Education Directory is a worthy companion whether you're planning a real or a virtual visit, providing hundreds of suggestions that could result in healthy hikes or visionary stories. It's practical, poetic and persuasive.
Every subject area can benefit from the addition of well-chosen objects.
Sarah Richardson gets children to work marvels with cereal or photocopier paper boxes, transforming them into drawing boards, filing systems or pieces of sculpture. Lengths of wire are requested from telephone engineers in the street and metamorphosed into jewellery or skeletons of plaster statuary. Sample pieces from carpet shops furnish dolls' houses, while cassette tape provides the inhabitants' hair.
Steve Telfer, humanities adviser for West Sussex, has many versatile and creative ideas for activities in geography that use items you can beg or borrow. "Calendar photographs and postcards stimulate children to investigate different kinds of places," he says. "There are countless varieties of maps that cost you nothing - from theme parks, transport companies, shopping malls (introducing a third dimension to show different floors) and tourist venues."
Science can also be furthered by freebies. Meg Post of Sphere Science devises intriguing experiments and investigations using various kinds of paper supplied by generous manufacturers. "Children find out how inks and adhesives work, about testing textures and strengths, then about classifying and communicating what they've learned," she says.
Ms Post also performs intelligible miracles with film canisters (volcanoes using bicarb, food colouring and vinegar) and plastic drinks bottles (paddle boats with elastic bands and lolly sticks).
So don't be scared to ask. Remember that people can only say "no" and that a "yes" is just as likely. Think carefully about what you really want. If your class is studying the Romans, it's a good time to visit a hardware shop and get some paint sample cards to use for making mosaics.
But don't hoard for hoarding's sake. That way, you will avoid being a miserable overburdened wraith, but become instead the happy and bountiful spirit of learning past, learning present and learning yet to come.