Challenges of Linking Digital Heritage Scientific Data with Scholarly Research: From Navigation to Politics

The Library of Congress has expanded its
digital spectral imaging research of humanities
artefacts that reflect the history of the United
States, with the development of advanced
imaging techniques that provide data for
the studies of manuscripts that span the
centuries: Portolan Charts – from 1320-1633,
Jefferson’s handwritten draft of the Declaration
of Independence from 1776, and Herblock’s
political cartoons from 1929-2001. Using
standardized digital imaging techniques, the
Library of Congress Preservation Directorate is
providing preservation scientists, conservators
and humanities scholars with access to
digital information on historic and fragile
documents with conservation-safe, non-
destructive technologies. This provides data for
greater understanding of the original object,
including revealing creation techniques, and
identifying the origin of the substrate (paper,
parchment) and media. The Library plans to
host this data in standardized format for access
as part of a broader preservation database of
scientific reference materials of naturally-aged
substrate, media (inks, colorants and pigments),
treatment effects, environmental data and other
document production and creation information.
These recent advances in technology and
digital access have paved the way for the
improved utilization and interpretation of
scientific analyses to contribute to scholarly
interpretations of heritage materials.
1. Integration of Imaging and Data
Management for Discovery
The Library of Congress has implemented digital
spectral imaging of the following objects to
collect preservation data, scholarly information
and a cross-section of data on cultural heritage
old and new:
-
Portolan Navigational Charts:
1
Imaging is
being used to non-destructively characterize a
range of pigments, details of compass points,
creation techniques and tools, and potential
palimpsest information.
-
The handwritten draft of the Declaration
of Independence:
2
Hyperspectral imaging
revealed layers of changes and different inks,
and offered new insights into the original
Jefferson text that was crossed out and
overwritten.
-
Herblock Political Cartoons:
3
A selection of
the large original drawings were spectrally
imaged to assess the condition of light
sensitive inks, also revealing details of the
drawings not previously discovered.
The application of digital hyperspectral imaging
and associated non-destructive technical
analyses to key cultural objects at the
Library of Congress required the integration
of complementary data to address a wide
range of preservation and scholarly challenges.
The advanced imaging data is incorporated
into ongoing humanities studies of objects,
generating digitally linked data sets in
standardized format for Internet access. The
non-destructive imaging capabilities allow
researchers to characterize pigments and media
on the artefact, retrieve hidden and lost
text, and illuminate production methods of a
range of cultural objects. Characterization of a
range of materials has been enhanced through
the development of a standardized spectral
reference sample set, virtually eliminating
the need for any sampling. Integration of
the data from these technological advances
with information from other preservation
studies, allows greater scholarly access to
the information available from fragile historic
documents on parchment and paper.
Application of non-destructive imaging
techniques allows the equivalent of optical