This is a guest post by James Thurn, a Preservation Specialist at the Library of Congress, Conservation Division.
The Library of Congress’ Geography and Map Division holds one of the largest, rare globe collections in the world. The Collections Conservation Section (CSS) in the Conservation Division is rehousing this collection in response to a request from the Geography and Map Division since the globes were housed previously in heavy, acrylic vitrines. Heavy vitrines make lifting them from the top of tall map cases difficult, placing both staff and globes at risk. The bases of vitrines are constructed of wood and adhesive, both of which may off-gas acidic compounds which will build up within the enclosed vitrines, potentially placing globes at further risk. Overall, most of the vitrines are larger than necessary, which consumes valuable shelf space. Thus, the rehousing project solves several problems.
Collections Conservation Section staff are replacing the acrylic vitrines with archival, corrugated board housings which are far lighter in weight than the old vitrines and will not off-gas acidic compounds. As of February 2025, over 50 vitrines have been replaced with archival, corrugated board housings, and the project is nearing completion.
Smaller housings (i.e., housings less than 35 cm tall) are created with the help of an automated box-making machine, however, larger housings must be constructed by hand. All housings are customized based on the interior, with trays to provide ready access to globes and foam cushioning to protect the globes. After housings are constructed, catalog information and photographs are affixed to the exterior of the housings as reference aids for staff and researchers.
An example of a rare globe rehoused recently is the Telegraphic Globe created by Savage & Co. in New York City in 1872. The locations of telegraph lines “…drawn by Samuel F.B. Morse expressly for this globe” are depicted. Topographic relief is represented by hatch marks.
This globe measures 31cm in diameter and is composed of paper gores mounted on a paper-mâché and plaster sphere. A wood stand with four legs supports the globe and allows the globe to swivel on its axis. Overall, the globe and its stand measures 46 cm tall and 43 cm wide. The empty acrylic vitrine weighs approximately 23 kilograms (50 pounds) and takes up a large amount of storage space.
An archival, corrugated board housing for a globe consists of three main parts: the base, lid, and tray. The first step is to measure the height, width, and depth of the globe. The desired dimensions of the housing are calculated by adding to the globe dimensions sufficient space for the tray and cushioning beneath the globe, space for cushioning around the perimeter of the globe, and 3 to 4 cm of space above the globe.
Once the desired dimensions of the housing are determined, the measurements for each side of the base are marked on a flat sheet of corrugated board.
Lines marked in red are cut using a utility knife and the dashed lines show where the board is folded. Hot-melt glue is used to adhere board where it folds onto adjacent surfaces. The lid for the box is made similarly to the base of the box. The lid is sized according to the dimensions of the finished base, allowing sufficient space between the lid and the base so the lid does not fit too tightly or too loosely.
Like the lid, the tray within the housing is sized according to the dimensions of the finished base. Construction of the tray is customized, accounting for the weight and geometry of the globe. A heavy globe requires reinforcement of the tray bottom using an additional layer of corrugated board, binder board, or a sheet of structural board with a honeycomb interior for strength and rigidity. Polyethylene foam covered in polyethylene sheeting is adhered to the bottom of the tray to provide cushioning for the base of the globe and to prevent shifting of the globe on the tray.
After the base, lid, and tray are constructed, the globe is placed in the housing to mark placement of cushioning around the perimeter of the globe. Cushioning consists of polyethylene foam covered with polyethylene sheeting and adhered to the walls of the housing using hot-melt glue.
The final step in the housing process is to affix caution labels, catalog information, and a photograph of the globe to the housing. If the globe is asymmetrical, an instruction label is affixed to the tray to ensure patrons return the globe to the tray in the correct orientation since the globe may not fit properly if placed in alternate orientations.
Once finished, the globe rehousing project will result in reduced risk to staff and globes when globes must be retrieved for researchers. Archival materials used to construct the new housings will not off-gas like the wood and adhesives used in the bases of acrylic vitrines, further reducing risk to globes. The new housings will facilitate access to globes for researchers requiring close examination of the globes. A final benefit of the project is the reduction of space occupied by globes in an environment where collections storage space must be optimized.
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Comments (4)
Thanks for this blog! It’s very interesting to see how you create a housing for such an unusually shaped object!
Clever. Please tell C Beyer she owes me a phone call.
What a huge improvement over the heavy acrylic vitrines. This is an impressive account of the skilled work involved in preserving our rare collections. We appreciate Mr Thurn and all the Preservation Specialists who work behind the scenes and do this important work.
James Thurn’s housing for the Telegraphic Globe is a beautiful piece of craftsmanship, and a great example of the wonderful work being done every day in the Conservation Collections section of the Library of Congress.
Moreover, his well-written description of the project was a pleasure to read. It shows an impressive mastery of technique, but also a genuine talent for intelligent, clear exposition. It gives me hope for the future that such gifted people have chosen to join the ranks of the guardians of memory.