Dr. Fenella France, Preservation Research Scientist at the Library of Congress, brought her expertise in preventive conservation to the topic of microclimates in cultural institutions, starting with the what, why, and where’s of microclimates, and ending with a presentation of an über-microclimate display and storage case: the “MOAC” (Mother of All Cases) for the iconic Waldseemüller map. Key points included:
- A microclimate is a environment maintained in a small space that differs from its external environment. This might be at various levels of control within a building: the building itself, a room, a case, a box.
- It is important to create specs for a microclimate based on an understanding of an object’s materials, history, and mechanisms of damage.
- A specific object’s materials and cultural significance may dictate its need for a microclimate.
- Issues which must be considered in planning a microclimate include the composition of the encasement, object access, environmental controls (active vs. passive), monitoring.
The Waldeseemüller map exemplified an object of highest cultural importance and value, which warranted an optimal microclimate for storage and display. Its fantastic encasement provided an anoxic environment, visibility of the object in storage and display, minimized handling, minimized oxidative and hydrolytic degradation, and access for monitoring of pressure, RH, T, and oxygen. A few amazing stats about the case:
- It was designed to maintain a 20-30-year seal.
- It is a 2200 lb case within another case.
- 92 bolts hold the tooled aluminum case together.
- It has maintained 0-30ppb oxygen.
- It has a flexible back to allow for changes in barometric pressure.
The encasement was an impressive, collaborative effort by conservators, engineers, architects, curators, and others. Although an estimated cost for the case was disappointingly not reported, I was impressed by the long-term planning that went into its design, as much as the elaborate, continuing monitoring and analysis conducted by the stewards of this object. Since the completion of the encasement in 2007, the durable case has proven to be effective and durable, as demonstrated by data generated by its monitoring systems. While I was duly wowed by the Waldeseemüller encasement, I would argue that France’s presentation of it as a “case study” was a little misleading. It was an exceptional feat of engineering and effort for an exceptional object. I was hoping for more discussion of more typical microclimate needs and solutions, probably covered in the Microclimate Workshop…