Evidence 77interacts with conceptual parameters. Architectural histori-
ans pose their questions of evidence, but the questions that
are available to historians depend on theories of architectural
history, to which historians knowingly or subconsciously
subscribe, that restrict the scope or import of the evidence
itself. Given these contingencies, the pool of evidence for an
architectural historian might include buildings, spaces, ruins,
cities and infrastructure; it might also include procedural
and design documents, commissioning notes and contract
documents, schedules of quantities and correspondence
with clients and authorities; it might include any manner or
representations of the ‘fi nished’ work, from watercolours
and engravings to depictions on television and in advertising;
it can include oral histories, letters between colleagues
or friends or relatives, newspaper reviews, and ephemeral
residues of all kinds, from tangible documents to the realm
of ideas.
It is safe to say that today there are few if any limits placed
upon the forms of evidence employed by historians of archi-
tecture, from the building that resists time to the evanescent
trace that is at time’s perpetual mercy. This has not, however,
always been the case. The relatively wide acceptance of an
open fi eld of evidence has been a hard-won battle of the
twentieth century’s later decades. It has much to do with
shifts over this same period of time in the appreciation of
what architecture itself can be. Indeed, whether the subject
of architectural history is a building, a historiographical
theme or a biographical fi gure, it is defi ned against a concept
of architecture and the architect. Historical research then
opens these concepts up to scrutiny. Given the iterative char-
acter of this perpetual exchange between research, knowl-
edge and concepts, there is no stability to the concept of
architecture, past or present. An architectural history can tell
its readers what is known and can be known of the past.
These are questions of evidence.
Few thesis advisers would suggest that a Ph.D. student in
architectural history research an architect with few extant
buildings, no known archive or body of ‘paper’ architecture,
and little presence in the architectural magazines of his or
her day. Such a project might bear an unpredictably high
yield of fruit, but it would be a risky investment – think of