Long-term monitoring of historic furniture

Jonathan P. Brown <envcons [at] csi__com> writes

>Has any protocol for this sort of long-term periodic monitoring of
>the physical condition of furniture (or analogous materials) been
>developed?

A belated response to Jonathan Brown's enquiry:

Here in the UK at the National Trust we have recently implemented
two systems for long-term monitoring of furniture, but neither have
been running long enough to make us feel confident that we have got
them right, so we have not yet considered publication.

Background:  The National Trust's 200 historic properties are
managed through 15 regional offices.  We employ regional and area
Conservators who are each responsible for housekeeping and
preventive conservation in one or more regions.

These Conservators train and assist the property staff responsible
for the day-to-day care, handling and cleaning of individual
collections.  Each property's staff includes a house manager, a
house steward and 2-3 conservation cleaners, but rarely a curator
(however there are 2 curators per region).

We also have specialist Conservation Advisers (both on the staff and
freelance consultants) who advise regions on remedial conservation
for the various categories of material, carry out surveys, recommend
priorities for treatment and approve freelance conservators to carry
out work to appropriate specifications.

Our problem:  Conservation Advisers' condition reports (reviewed and
updated every 5 years or so) describe in terminology familiar to
conservators the condition of each item of furniture, textile, etc.
Owing to lack of resources, this description is not yet supported by
any photographic documentation.

Property staff do not have direct access to these specialist
reports, and cannot easily interpret the relative significance of
what is described.  Not surprisingly, property staff (who change
every few years) tend suddenly to report apparent cracks and
scratches as 'new' or 'worse', when the damage may in fact have
remained largely unchanged for 15-20 years.

Our solution:  Two monitoring systems have been set up with advice
from the Advisers for Conservation of Furniture, and are implemented
within the regions by the Conservators and the property staff.  The
aim is to reduce anecdotal evidence of changing conditions, increase
informed observations and recorded fact, and ensure greater
continuity of knowledge and appropriate care at the properties.

    1.  Regional Conservators measure significant cracks in
        furniture, panelling, and (occasionally) panel paintings at
        regular intervals using feeler gauges and/or callipers, and
        these measurements are correlated to data from 24-hour
        environmental monitoring.

        This monitoring is being carried out, for example, at Knole
        near Sevenoaks, where the 15-17c house has been unheated for
        50+ years, and the rare and highly important 17c furniture
        and textiles suffer from high RH, mould and pest
        infestations.  The gradual introduction of environmental
        control (electric oil-filled radiators controlled by
        humidistats) aims to reproduce all year round the most
        favourable RH conditions that have occurred naturally in the
        house during summer months, and these may continue to be
        slightly higher than our normal target range of 50-65% RH.

        Our aim is to identify and monitor any dimensional changes
        that occur in vulnerable objects as a result of introducing
        environmental control, as distinct from those changes which
        occurred previously in 'natural' RH conditions.

        2.  Conservators identify up to 10 objects per category of
            material at each property whose changing/deteriorating
            condition gives particular cause for concern.  With the
            help of conservators, house staff have started to
            complete simple forms which describe (in terms they
            understand) the materials and construction of the
            object, the damaged area, and the agreed plan for its
            care (this specific care falls outside general
            guidelines described in 'The National Trust Manual of
            Housekeeping' (Viking Penguin, revised edition, 1993)).
            The form includes space for an annotated and measured
            diagram or sketch, and/or photographs, and for recording
            observations and comments at subsequent inspections.
            Copies of the form are available on request.

We are still developing our ideas and forms, so comments and
suggestions would be welcome.

Helen Lloyd
The Housekeeper
The National Trust
+44 171 447 6509
Fax: +44 171 447 6424

                                  ***
                  Conservation DistList Instance 12:36
                 Distributed: Tuesday, October 13, 1998
                       Message Id: cdl-12-36-001
                                  ***