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Issues in Science and Technology Librarianship
Summer 2011
DOI: 10.5062/F4TD9V7K

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American Woods: Conservation of a Unique Item

Tierney Lyons
Reference Librarian
Penn State Worthington Scranton
Dunmore, Pennsylvania

Copyright 2011, Tierney Lyons. Used with permission.


Romeyn Hough's The American Woods: exhibited by actual specimens and with copious explanatory text (1888-1928) stands as a valuable and unique title in the field of forestry. It contains paper-thin wood samples requiring special handling and conservation to prevent damage and disintegration. This article discusses why libraries and other institutions should consider this unique item for preservation selection, what conservation measures Penn State Libraries has taken, and what other types of preservation efforts have already been achieved.


In 1888, Romeyn Beck Hough began publishing The American Woods: exhibited by actual specimens and with copious explanatory text (American Woods), a multi-volume set containing paper-thin wood samples. The origin of the American Woods is as unique as its content. Hough wrote and published this extraordinary set over a 25-year period using specimens he collected himself with a specialized slicer he developed and patented in 1886. As the MARC record denotes, each case contains a booklet of descriptive text and at least 25 plates in its 14 volumes, covering 354 species with 1,056 wood samples. Each tree is described by its botany, habitat, physical properties, uses, and medicinal properties with tree names in five languages. The plates, printed in gold on black paper over cardboard, have cutouts for the mounted wood samples, showing transverse, radial, and tangential sections.

Originally planned as a 15-volume set, the first 13 volumes were published between 1888 and 1913 in three editions. In 1928, his daughter, Marjorie Galloway Hough, completed the 14th and final volume using her father's prepared samples and field notes. He intended to include all the important woods in North America and covered the Northern Atlantic states, the Middle West, Canada, the Pacific Slope, and the Gulf states in the completed volumes (Bernier 1916, p. 286). Some trees available at the time are now very rare, making this comprehensive American dendrological monograph even more precious.

During the time of publication, the work received great reviews and accolades. An 1893 new publication review states "this collection ought to be in every public school and library in the country" due to its flower, leaf, and fruit keys that aid in species identification and its wood slice mountings that show their structure, texture, and color ("American Woods" p. 529). An 1898 book review describes it as a great value for educational and commercial purposes, declaring, "It is absolutely without rival, and as long as there are trees in North America it will continue to be a standard work" ("Hough's 'American Woods'" p. 471). A later review, in a 1912 issue of The Literary Digest, calls it "one of the most valuable contributions to the literature of forestry" ("Hough, Romeyn B." p. 701). The reviewers then commented on the work's scientific value, beauty, and usefulness to woodworking professions such as architects and cabinetmakers, and to the study of forestry and botany as deforestation was coming into the United States' awareness. An obituary in Science reads:

Romeyn B. Hough has made a rare contribution to American botany in a model book, and especially in a series of illustrations consisting of the wood themselves--which, unlike texts and drawing, never can become out-of-date nor be found to contain untruths except as the names applied in his day to the trees he sectioned undergo change with progressing knowledge (Trelease 1924, p. 398).

Attesting to his publication's importance, Hough won the 1908 Elliott Cresson Gold Medal, the Franklin Institution's highest award, for his contribution to the characteristics and uses of American woods. By 1889, American Woods received the grand prize at the Paris Exposition, and by 1911, Hough had won gold medals at the Columbian, Pan-American, Louisiana Purchase, and Alaska Yukon Expositions ("Hough, Romeyn Beck" pp. 171). The combination of his wood machine invention, cutting wood at as small as 1/1200-inch thickness, and his devised process of sectioning wood in creating his publication led to these many awards.


Selection Criteria

Awareness of this special situation is important due to the set's appearance, value, and uniqueness. Each volume is encased in a book-like cover and, without examination, might pass as a traditional monograph. In addition, libraries' move toward more digital collections may lessen staff opportunities to encounter deterioration during use, processing, stack maintenance, and other special projects. Beyond workflow selection, Carolyn Harris (2000) provides two additional ways of detecting appropriate candidates for special handling, "value or uniqueness," and "vulnerability to loss or deterioration" in her book chapter, "Selection for Preservation" (Chapter 12, p. 210). Hough's title matches these criteria as it has high monetary value and its uniqueness makes it vulnerable to loss.

Appraisal and booksellers' listing prices indicate its monetary value. During a July 2009 Antique Roadshow, appraiser, Ken Sanders, appraised a 1910 third edition set for $30,000 because it was a rare complete set with each volume from the same edition and was in excellent condition. A rare bookseller and Antiquarian Booksellers' Association of America member, Sander states, "'s one of the most sought-after sets of the 20th century" ("Denver" 2010). Bookseller listings concur with prices ranging from $27,000 to $46,000 and remark that auction sale history shows only two complete sets sold in the last 25 years. The art auction company Christie's states that $92,100 is the price realized for a set sold in 2000. Interestingly, bookplates reveal that the sold piece was gifted to a Massachusetts public library ("Romeyn" 2009).

Uniqueness is demonstrated by inclusion of actual specimens, especially those of endangered trees, making it an item that cannot be easily duplicated today. Each volume was published as orders were placed and could be purchased individually without an entire set being manufactured, thus leading to a rarity of complete sets (Dengler 1980). In addition, each instance of the book is completely distinctive because the wood slices placed in it are unique.

Harris's chapter (2000) on preservation selection covers criteria for decision making on the item level, where again, American Woods passes the test. Criteria include artifactual value, importance to the discipline, and permanent research value.

Artifactual value is demonstrated by its age and unusual illustrations that aid in the understanding of its subject matter. Harris points out that the National Archives and Records Administration, along with the Library of Congress, have policies on retaining materials in original formats, and states that the carrier of the information also conveys that information (p. 214). Therefore, seeing the finely sliced wood samples, suitable as transparencies or under a microscope, provides meaning beyond a photograph of the same cross-section.

Hough's publication holds value as an educational resource. Every Normal School in New York State used the first volume at the time of its publication, and a 1944 Funk & Wagnall's dictionary used Hough's wood samples for a full-page color example of typical American forests (Dengler 1980). The nation's first forestry program, the Biltmore Forest School (1898-1913), relied on Hough's set as one of the only discipline-specified textbooks focused on North America (Special Collections Research Center, NCSU Libraries 2003). The adoption of his work for training teachers and foresters, and in a standard reference book, show the success of the title as a pedagogical tool.

Today one can find three 1887 prospectuses in the Library of Congress's American Memory historical collections advertising Hough's forthcoming book. American Memory documents the American experience and serves as a national educational resource. The pamphlet, leaflet, and wooden card are held in the Library of Congress Printed Ephemera collection in both hardcopy and digitized formats, thus showing that even ephemeral American Woods documents are worth keeping for future study.

Permanent research value is seen in its continued inclusion in library collections. A search of WorldCat, a library catalog searching thousands of library holdings, shows approximately three hundred libraries worldwide with the fourteen volumes or partial sets; about the same number have the revised 1957 edition called Hough's Encyclopaedia of American Woods, and nearly two hundred, particularly in Europe, have a reprint entitled, The Wood Book.

Hough's Encyclopaedia of American Woods was possible because Hough collected thousands of extra samples for an eventual revised publication (Dengler 1980) and two professors from the Duke University's School of Forestry penned it. The Wood Book, prepared by Klaus Ulrich Leistikow and Holger Thüs, was published by Taschen in 2002. It contains photographs of original plates and is housed in a wooden case. A second edition, entitled The Wood Book: the Complete Plates was published in 2007. This more affordable and accessible reprint sparked new interest in the original and received positive reviews, especially for its high quality facsimiles of the specimens.

At least two libraries digitized the wood samples and made them freely accessible via their web sites. Yale University's Beinecke Rare Book and Manuscript Library undertook the project because the book is highly sought for the samples' beauty, stating that the specimens' age add to their ecological value ("Library Exhibit" 2007). North Carolina State University Libraries' Special Collections Research Center digitized the set as part of their web-based resource for forestry history research in their state (Special Collections Research Center, NCSU Libraries 2003). Click here to see a sample page from their collection. Two universities selecting this work for digitization demonstrates the work's continued educational and historical significance.

The revision, reprint, and digitization are three important preservation efforts. They have made the information available and accessible in different formats and allowed the original to be protected.

Finally, financial considerations are criteria for preservation selection; however, the strategy implemented at our institution proved relatively inexpensive and other libraries should find the process to entail little staff time, also helping to keep costs down.

Preventative Conservation

These veneers require special handling and conservation to prevent damage and disintegration. Conservation for our purposes is "a need to retain the integrity of an item in its original format or design" (Buchanan 1990, p. 9). In this case, the wood samples require conservation because they become brittle in an average library setting.

Wood specimens fall outside the standard preservation guidelines. Normally books need storage with 40-55% relative humidity and an approximate 60 degrees Fahrenheit temperature year round because frequent fluctuation can harm them. Non-book materials, such as photographs, paper, and computer discs, require even lower humidity (Balloffett & Hille 2005, pp. 2, 190). High humidity invites insects and mold, whereas low humidity leads to embrittlement. Ideally the humidity should stay within a 5% range of the starting point to limit risks of damage, a situation rare in most buildings (K. Dabney, personal communication, September 2, 2010). American Woods is a special case because its thin wood responds rapidly to change, expanding with increased humidity and contracting as it dries. This item needs very consistent humidity to prevent the specimens from cracking.

To better care for this set, we moved it into a preservation enclosure, removing it from shelves that see humidity fluctuations and seasonal dryness during the building's winter heat. After only forty years, bibliographers were starting to see wear and suggest special care. Seen in his book first published in 1955, Blumenthal warns that "save for exception purposes, their tenderness precludes much handling" calling the piece remarkable and rare, denoting the lumber's grain as defying description (1969, p. 71). Although it left the stacks location, its reprint, Wood Book, and its republication, Hough's Encyclopaedia of American Woods, serve as replacements in the circulating collection.

To care for the original, our conservator, Karen Dabney, established a more stable environment for the volumes. She created a preservation enclosure using sealed bags supplemented with humidity indicator cards and plastic storage containers. Humidity indicators are inexpensive cards with a moisture sensitive chemical that changes color when the relative humidity increases. A usual preservation method of restraining the books in a study phase or clamshell boxes offer protection, but lacks sufficient dryness prevention. After consulting the conservation literature and discussing the project with other conservators and conservation suppliers specializing in microclimate systems, Dabney selected a system with effective humidity control, durability, and ease of use.

Owning 48 volumes across three Penn State libraries, we decided to store the books stacked in plastic bins to reduce storage space. Unable to locate airtight archival plastic containers large enough for multiple monographs, we chose inexpensive, lidded, polypropylene plastic containers to keep the volumes together and protect the bags from mishandling. Lining the bins in archival corrugated board for cushioning and protection from the plastic's off-gassing, we then bag-sealed the books.

Re-sealable laminated multi-layer barrier film bags engineered for effective moisture barriers offered protection within the bins. Of the two options, we selected Escal Ceramic Barrier Film, a ceramic laminate vacuum-mounted to a PVA layer and sandwiched between polypropylene and polyethylene plastic. Its transparency allows us to view the humidity indicator cards and therefore more easily monitor the environment, and the puncture-resistance protects the stacked materials. We then enclosed the bags with re-sealable plastic clips, called Keepsake clips, proven to form a good moisture barrier (see Appendix).

The timing of bagging the volumes proved important, as Dabney (personal communication, September 2, 2010) explains:

I wanted the climate control system for American Woods to be simple and easy to use, and not require the technical expertise and time needed to set a new relative humidity within the package, which could be done using silica gel that was specially conditioned at 50% RH, and would need to be periodically rejuvenated. Instead I chose the more practical and more easily attainable strategy of using a passive system that would maintain the starting humidity or allow a slow, gentle, gradual change over time. We had to start with the most optimal humidity during the year, and try to keep the books at that level...Knowing that the air had a higher humidity in the summer, we let the books acclimate to that humidity over the summer and waited until later in September to seal the books in the Escal bags. This way, the books would tend to remain at or near the summertime humidity level, or experience a gentle and gradual decrease in relative humidity that was fairly minimal. This system would prevent the dramatic decrease the books have traditionally experienced while unprotected in the stacks.

Using this approach, the system has maintained the needed humidity over the last three years.

Costs vary depending on supplies selected and variability in order size. Some items require a minimum bulk order or are sold by the case. The system cost approximately $150 to $700 for 14 volumes, equaling approximately $10-50 per book. The lower estimates suggest cost sharing among libraries and cost cutting by excluding the optional humidity cards, archival corrugated board, and polyethylene plastic bins.

Results and Discussion

Maintenance is minimized by using a passive system, noting that books and veneers hold their conditioned humidity for short periods outside the microclimate bags. However, staff should return the books to their microclimate as soon as the patron finishes using them and remove air from the bags before resealing them. In addition, monitoring the humidity indicator cards monthly verifies that the humidity inside the bags remains fairly constant.

If the books see heavy use, spending extended periods outside of the bags, or if the storage rooms encounter a long-term humidity change, then the storage humidity might drop too low (below about 30%). Decreased humidity is reversed by adding Art-Sorb or RHAPID PAK specialty silica gel sheet, cassettes, or moisture permeable conditioned to 50% relative humidity. To date, we have avoided the need to add silica gel.

Time and cost came into play on this project; however, we achieved an effective solution that conserved an important piece of the sciences collection for years to come. Given the success of this project, we achieved effective conservation of an important and unique scientific reference source.


I thank our conservator, Karen Dabney, for implementing an effective solution for this unique case and her interview regarding the process. Thanks also goes to John Burke, Chief Conservator of the Oakland Museum and John F. Kennedy University professor, and Jerry Shiner, founder of Keepsafe Microclimate Systems and a custom materials supplier, for their insight and recommendations. I acknowledge Amy Paster, head of Penn State's Life Sciences Library, for identifying the need to save this resource, initiating the project, and the suggestions and encouragement to write this article."


American Woods. Exhibited by Actual Specimens. Romeyn B. Hough, Lowville, NY. 1893. [Review of the book The American woods: Exhibited by actual specimens and with copious explanatory text, by R. B. Hough]. Garden and Forest: A Horticulture, Landscape Art and Forestry, VI, 529-530.

Balloffet, N. and Hille, J. 2005. Preservation and Conservation for Libraries and Archives. Chicago: American Libraries Association.

Bernier, R.L. 1916. Hough's "American Woods". In R. Bernier (Ed.), California's magazine (Edition De Luxe ed., Vol. 2, pp. 285-289). San Francisco: California's Magazine Co.

Blumenthal, W.H. 1969. Bookmen's Bedlam: An Olio of Literary Oddities. New York: Books For Libraries Press.

Buchanan, S. 1990. Preserving Library Resources: A Guide for Staff / prepared by the Standing Committee on Preservation ; chair Sally Buchanan ; Mary Kay Johnsen ... [et al.]. Pittsburgh, PA: Oakland Library Consortium.

Dengler, H.W. 1980. Remembering Romeyn Beck Hough. Journal of NAL Associates 5(3/4): 84-87.

Denver, 2 Hour (#1411). 2010. [Television series episode]. In Bemko, M. (Producer), Antiques roadshow. Boston: WGBH Educational Foundation. Available from

Harris, Carolyn. 2000. Selection for preservation. In P. Banks, R. Pilette (Eds.), Preservation: Issues and Planning (pp. 206-224). Chicago: American Library Association.

Hough, Romeyn B. American Woods, Part XII. Lowville, N.Y.: Romeyn B. Hough, Publisher. 1912. [Review of the book The American woods: Exhibited by actual specimens and with copious explanatory text, by R. B. Hough]. Literary Digest, 44(1146), 701.

Hough, Romeyn Beck. 1967. In The National Cyclopaedia of American Biography (Vol. XX, pp. 170-171). Ann Harbor, Michigan: University Microfilms.

Hough's "American Woods." 1898. [Review of the book The American woods: Exhibited by actual specimens and with copious explanatory text, by R. B. Hough]. Recreation, IX(1), 471.

Library exhibit showcases books that feature images of trees. 2007, April 6. Yale Bulletin & Calendar 35(24). Retrieved from {}

Romeyn Beck Hough (1857-1924) 2009. Retrieved from Romeyn Beck Hough (1857-1924) (2009). Retrieved from

Special Collections Research Center, NCSU Libraries. 2003. [Internet]. [Updated 2010 July 22]. History of forestry: An NC ECHO Project. North Carolina State University Libraries' Special Collections Research Center. Available from

Trelease, W. 1924. Romeyn Beck Hough -- 1857-1924. Science, 60(1557): 397-398.


The supplier, that assisted in materials selection and provided the microclimate bags and re-sealable clips, is reached at the following addresses and telephone number:
Keepsafe Microclimate Systems
9 Oneida Avenue
Toronto, ON CANADA M5V 1M3
telephone: 416-703-4696

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