By ELMER EUSMAN
In 1916 the U.S. Indian Office transferred a unique map by the Jesuit missionary Pierre-Jean de Smet to the Library of Congress. The hand-drawn 1851 map outlines the territories of various Indian tribes in the West, extending from the Canadian border on the north to the Arkansas River on the south, and the Missouri River on the East to the Columbia River on the West. De Smet was able to compile this map using the knowledge he gleaned from his extensive travels through the West and from the local Indian tribes, all of whom held him in high regard.
In 1851 de Smet assisted in securing a peace treaty between the United States and a number of Indian tribes at a general council held at Fort Laramie. Because of his extensive knowledge of the Native American tribes, the government asked him to create a comprehensive map of the West, delineating the territories of the various tribes.
The map that de Smet made measures 35 inches by 53 inches and is completely hand-drawn in brown ink and watercolor. The map shows rivers, mountain ranges, towns, forts and state and territorial borders; it even features a decorative border with flowers and a portrait of an Indian chief named "Big Robber." However, the main significance of the map is its depiction of the location and extent of various Indian territories in the American West in 1851.
To a certain degree, the condition of the map before conservation treatment reflected the hardships endured by de Smet himself. The map had traveled widely and been heavily used; over time it had been subjected to a number of questionable repair treatments. The result was a map that was so damaged that it could hardly be consulted, much less displayed, without doing further damage to the document.
The most noticeable damage was the large number of tears, which had effectively divided the map into more than 100 small fragments. An attempt to stabilize the map had been made in the past by pasting a cotton fabric lining to the back of the map. Unfortunately, this created more tension in the paper, resulting in even more damage. The damage was compounded by a layer of chiffon silk that had been added to the front surface of the map, causing extensive discoloration that gave the paper a brown appearance.
The treatment of the map was further complicated by the vulnerability of the watercolor medium. In order to remove the cotton fabric lining, the chiffon silk and the associated paste, the map had to be washed. However, the use of water could have adverse effects on the watercolor, potentially resulting in some loss.
Because of the complexity of the map and its condition, the Library's Conservation Office decided to approach the treatment of the map with a team of eight experienced conservators. This approach, although unusual in paper conservation, turned out to be very successful, because each of the conservators was able to contribute a part of the solution. The core group of conservators were Sylvia Albro, Julie Biggs, Elmer Eusman, Annlinn Grossman, Mary Haude, Holly Krueger, Linda Morenus and Heather Wanser, with additional help from Otoyo Yonekura, Cynthia Karnes and Lida Husik.
The fragility of the paper was the first factor that needed to be addressed. Treatment was going to place additional physical stress on the map, and, therefore, it needed to be reinforced ahead of time. Conservators applied a facing of Japanese paper to the front of the map to prevent further tearing and help keep the many fragments in place.
The next phase of treatment involved removing the cotton lining from the back of the map. This took many hours of careful wetting and scraping. At the same time, conservators needed to prevent excess water from reaching the front of the map and affecting the watercolor base. It took five days of work, but finally the team succeeded in removing most of the paste.
The map was now ready to be washed in an enzyme solution to remove the remaining paste residue and help dislodge the chiffon silk from the front surface. Enzymes are highly specific chemical compounds that react only with one specific chemical product: in this case, the starch paste. Although the colors had been tested extensively for solubility in water, the conservation team was relieved to see that all colors held beautifully. The facing, the chiffon silk and much of the discoloration and paper degradation products were washed out during two enzyme baths and additional rinsing baths. The map regained much of its former splendor with lighter paper and brighter colors.
Once the cotton lining was removed from the back of the map, there was nothing to hold it together; and after it was dried, the map consisted of more than 100 small fragments. Conservators properly aligned all of the fragments and repaired all of the losses, which were filled with paper pulp. Paper pulp is a water solution containing suspended paper fibers. When paper pulp is applied to an area where there has been a loss, and then dried, it creates a new layer of paper within that area.
Finally, conservators gave the map a new lining of two layers of Japanese paper. Japanese paper is thin but very strong, and it does not cause the tension that cotton fabric does. The final result was a perfectly aligned, flat map.
Apart from minor toning of some of the areas of the map where losses had occurred, conservators did not have to fill in any of the original design on the map. The pulp color blends in well with the original paper of the map, and one can hardly distinguish the losses at first glance. Upon closer inspection, it is clear that small areas are missing, but this does not interfere with the ability of the viewer to appreciate the map much the way it must have appeared when it was first created in 1851.
Elmer Eusman is a senior paper conservator in the Library's Conservation Division.