One of my favourite places in the world is a museum store. I love being in an ice-cold warehouse surrounded by shelves and shelves of exciting cardboard boxes labelled with tempting codes which entice you to open the box and view the goodies within.  Or not labelled so you have to open the box to see what’s inside. Or even more intriguing, different labels on the two ends of the box. Or glass-fronted cupboards full of almost complete pots or a stone coffin complete with skeleton or…. But perhaps you may ask, and rightly, why is all that stuff that never goes on display and the public never sees being kept there at the taxpayers’ expense?

Most of this stuff comes from archaeological excavations. When a dig takes place, the finds will initially go to the headquarters of whichever body is carrying out the dig. When they have done the necessary studies and the site has been published, the finds will usually be deposited in the county museum and the archive, plans, sections and paperwork will also be stored somewhere suitable. So any local authority museum is faced with an ever-increasing mass of finds, very few of which will ever go on display. Only a very few finds from excavations, things like the Scar plaque, are worth putting on display. It would be impossible to display fifteen tons of squashed sherds of Grooved Ware, or half a roomful of butchered cattle bones and they wouldn’t be very interesting to look at either. But that is not what they are there for. And you can’t throw them out to make space for new ones.

The important thing in any science is that any scientist can test conclusions that have been published and see if they are valid. If you are doing this in say, chemistry, you can just get hold of some apparatus and chemicals and do the experiment all over again and see if you get the same result. But in archaeology you can’t do this. Excavation destroys the evidence as you retrieve it. You have to have the original objects and the detailed records of how they related to each other if you wish to reconsider someone’s conclusions. A few years ago an archaeologist looked again at a collection of human bones in Kirkwall museum and came to a totally different conclusion to the original bone specialist. No doubt further study will extend the argument even further. This couldn’t have happened if the bones hadn’t been kept after the excavation was published.

New techniques are being developed all the time. Recently, in this same museum, two international projects have revisited the finds from excavations carried out years ago and published at the time. They were using newly-developed techniques on this material. One was looking at the particles trapped in dental calculus on 5,000 year old human teeth, which can tell you the most amazing things, for example which spring these people got their water from, and what they had been eating. The other was collecting residues from 5,000 year-old potsherds to use for enhanced methods of C14 dating. If those shelves and shelves of boxfuls of human skeletons and smashed potsherds had been discarded on the grounds that they were already fully published, all this new information would have been lost.

I have a particular interest in the problem, as a piece of research I was once involved with at another museum came to something of a full stop because a large number of the finds I needed to look at had been thrown away. Someone had written a report on them which they considered adequate at the time and then discarded them, keeping only a few sample pieces. They were medieval glazed roof tiles, which of course are bulky (although rather pretty).

Of course it is impossible to keep indefinitely all the masses of broken brick, stone, and smashed up animal bone that come out of the ground on large excavations. Some of it has to be thrown away, preferably before it gets into the museum store. But you have to make sure that you throw away the right stuff, for example, most of the material from mixed or contaminated layers, where finds from many different periods or centuries have, by various processes, been jumbled up together. But it still means a large and ever-increasing quantity of finds in the store.

And of course there are all the social history finds which do not come from excavations but which have both their own historical value (or not) and their own problems. A faded postcard of the local artillery battalion during WWI doesn't take up much space. A small fishing boat with a hole in it does.

And somebody with the right training has to look after all that stuff. Someone has to know what is in that store and where it is, so that they can arrange access for people doing research on the objects. It’s no use having the best collection of spindle whorls in south-east England if nobody knows which of two hundred boxes they are stored in. Somebody has to make sure that the temperature and humidity of the store is suitable at all times. I once spent six months breathing in Rentokil fluid in a leaking amateur storage facility in England, repackaging pottery that had got loose when the cardboard boxes it was packed in had got damp and collapsed. Good job the sherds were individually marked (most of them). Someone has to see to the packaging of the objects, stacking them so that the ones underneath don’t get squashed by the ones on top. Someone has to prevent moths and beetles from eating the wood and the textiles. Someone has to make sure that the fire alarms and burglar alarms are working, and that PhD students who are studying material in the store don’t walk off with objects to use in their evening classes (yes, this was rumoured to have happened at a national museum when I was young). These are only a few of the things that have to be taken into account. And there are also the Health and Safety issues to consider.

It is right that the general public, whose taxes and donations keep many museums going, and the members of the local council who allocate funds, should ask why a museum needs both a bigger store and people with university degrees who earn a staggering 27K per year to look after it. We have to explain to them that many earth-shattering discoveries in archaeology are made, not outside on site, but inside an old warehouse, by someone taking another look at boxes of finds which have been carefully looked after by someone like me.