Friday March 29 2019
Visitors to The Red House and its associated public areas may have spotted, in corners or inside display cases, small white objects with display screens and aerials, looking like old-fashioned mobile phones. You may never have noticed them: they’re not meant to be obtrusive. But these little devices are a key element in how we care for our collections: part of our environmental monitoring system.
Each device monitors conditions constantly, noting temperature and relative humidity. That ‘relative’ is important: the atmosphere’s capacity to hold water vapour is different according to how hot or cold it is. The same amount of water in the air might be carried comfortably at twenty degrees Centigrade, but if that same air is cooled to below ten degrees it may struggle to hold all that water. Relative humidity measures, as a percentage, how close the air is to carrying its maximum amount of water vapour: once one reaches 100% one is at the point where water begins to condense out of the atmosphere as dew, our nightmare scenario since it leads to water damage and potentially mould growth. Temperature and relative humidity are interlinked, then, and carry out a continual dance, with a drop in temperature causing relative humidity to rise, and vice versa: a dance we monitor with these devices.
Each little unit transmits continuously to a central monitor in the archive building, so that we can see conditions across the site at a glance. Every fifteen minutes, each unit’s readings are recorded and stored in a data file so that, if needed, we can construct a long-term record, either as a huge spreadsheet or a simpler graph. It’s important that we can do that, not just so that we can track long-term trends for our own use, but also so that we can report to other people: being able to do this is a condition of the Government Indemnity Scheme, which insures material held here on loan. That includes, for instance, the painting of Britten’s nieces and nephew at the top of the Red House stairs, on loan from the family. For our current exhibition Tippett & Britten: Portrait of a wartime friendship, the British Library needs regular environmental readings for the material it has lent us, including the very fragile score to A Child of Our Time, and the last thing to happen before the exhibition cases were closed and locked was that monitors – newly back from their annual recalibration – were placed in the cases with the manuscripts.
So, you may never have noticed these little devices or paused to look closely at them: but next time you see them, give them a thought, as they tick away unobtrusively doing a vital job.