So, we had quite a problem. We had some truly huge bone to prepare, store, and make available to researchers. But these bones were extremely heavy, and although they had perfect surface detail, they were riddled with cracks that penetrated through to their worryingly sizeable marrow cavities so they had very little internal strength.

The limb bones were like fragile hollow tubes, shattered throughout their length, just waiting to fall apart if you tried to lift them unsupported.

Although the limb bones presented us with a particular suite of challenges, all the specimens were quite fragile, and, given the scientific importance of the material needed to be handled very carefully. Throughout the project we chose the least invasive techniques, trying to preserve the integrity of the material as much as possible. All the specimens were cleaned with the method that would be gentlest in each case, moving on to more serious preparation tools as the matrix on the specimen required.

For all the specimens we would start cleaning off the sediment with soft brushes (after removing the topside of the plaster jacket in the case of the limb bones, skull and tusk) and progressed to wooden tools for stubborn sediment, to compressed air, then the airbrasive machine using only sodium bicarbonate. The very last resort, for specimens with a lot of mineral matter adhering to the bones, would be an engraving tool, which was used to vibrate individual grains until they flicked off, rather than to gouge out chunks of matrix.

As we were preparing one of the largest and most complete elephantid skeletons in the world using a microscope for all mechanical preparation, we were fortunate to have got the project completed inside of 4 person-years.

The only chemicals used on the whole collection of over 400 specimens were the methacrylate co-polymer Paraloid B72 used with acetone. It was used as an adhesive, as a consolidant, and as a gap-filler. I decided to use just the one product, as it is the most tried and tested, stable, reliable and reversible adhesive there is. It is particularly useful for subfossil material, penetrating it well, and it bonds very well to itself. It is best to utilise just the one product, as otherwise you can create a cocktail of chemicals, and you cannot be sure of the long-term stability of the situation you are creating. For the gap-filler I mixed Paraloid B72, at 25 percent in acetone, with the inert airbrasive powder No.9 glass beads, as detailed in the article published in The Geological Curator in 2000 (see below).

However, we made sure that the consolidant and adhesive was always used extremely sparingly on the material. There have been leaps and bounds in the last few years in dating methods, DNA extraction, dietary analyses and other isotope studies of subfossil material. Heaven knows what they'll be able to tell us about our specimens in another 50 years time - if we don't adulterate them with an overdose of adhesives as soon as we get our hands on them, that is. New biomolecular and dating analyses are not only popping up all the time, but the age of the material that can be used is constantly being pushed back. DNA is currently thought to deteriorate over about 30-40,000 years. The WRE material is 650-700,000 years old, but it looked in such good condition that we took samples of it anyway for amplified DNA analyses at the Natural History Museum, just to push back the boundaries of failure - which we did with resounding success.