Wood Identifications from the Aramingo Canal Timbers
437 High Street
Burlington, NJ 08016
Fiske Center for Archaeological Research
University of Massachusetts Boston
Boston, MA 02125
Cultural Resource Management Study No.35
January 22, 2010
Nine wood samples from timbers from the Aramingo Canal site were submitted to the Fiske Center’s Paleoethnobotany Laboratory for taxonomic identification.
Samples were identified by comparison with published descriptions and modern reference wood specimens housed in Paleoethnobotany Lab at the University of Massachusetts Boston. Each wood sample was examined in three sections (transverse, tangential, and radial) using a Zeiss dissecting microscope at magnifications of 10- 30x and a Nikon metallurgical microscope at magnifications of 100 – 600x. Identifications were typically based on wood microstructures.
All of the wood samples were softwoods from the Pinaceae (pine) family (Table 1). The majority of the wood samples were Tsuga sp. (hemlock). Given the location of the site, the Tsuga specimens are probably Tsuga canadensis (eastern or Canadian hemlock). Eastern hemlock has a geographic distribution from Quebec, Canada south to Georgia from the east coast to Minnesota and Missouri . Only two specimens (FS 54 and 56) were of Pinus sp. (pine), and based on micromorphological characteristics (window-like cross-field pitting and nondentate ray tracheids) these pieces of wood were of a soft pine (Pinus strobus, P. monticola, or P. lambertiana); given the location of the site, the wood pieces are probably Pinus strobus (eastern white pine).
|Sample #||Taxonomic identification||Common name|
|FS 49||Tsuga sp.||Hemlock|
|FS 51||Tsuga sp.||Hemlock|
|FS 52||Tsuga sp.||Hemlock|
|FS 53||Tsuga sp.||Hemlock|
|FS 54||Pinus sp.||Soft pine|
|FS 55||Tsuga sp.||Hemlock|
|FS 56||Pinus sp.||Soft pine|
|FS 57||Tsuga sp.||Hemlock|
|FS 58||Tsuga sp.||Hemlock|
Both pine and hemlock were common large conifers in northeastern forests. Historically white pine and hemlock tend to be dynamically co-dominant in old growth forests in New England, and they are presumed to be a major component of the pre-European settlement of northeastern forest . Hemlock is a shade tolerant, slow growing tree conifer while white pine tends to grow faster but is shade intolerant. After disturbance such as land clearance or fire, white pines with their fast growth in open environments expand rapidly, while hemlock tends to be outcompeted. Hemlock expands in later successional stages where hardwoods begin to dominate .
White pine extremely valuable for timber since European colonization. It was a highly sought after tree for timber and more expensive than hemlock. There was heavy demand originally for ships’ masts and later for lumber for construction but the wood was used for a wide variety of purposes . Some have suggested that the original northeastern stands of white pine were thoroughly logged by 1840s and production moved to the Great Lakes states .
In historic times, both trees were heavily logged for their valuable lumber, although white pine was considered more valuable. Hemlock is still used today for lumber but is generally considered rather poor quality because it tends to be brittle. It is used for light framing and roofing . Historically, the most intense use of hemlock was between 1890 and 1910 .
Hemlock bark was among the most commonly part of the hemlock tree used because it provided tannin for tanning shoes and other leather goods, but the wood was commonly used for structural timbers and flooring in houses and other buildings. From my brief examination of historical records, it appears that hemlock was preferred wood for timbers placed below the waterline. Perhaps more to the point, hemlock logs were used in canals, piers, mill dams, and sewer pipes. During the 18th century, hemlock logs were bored to create pipes for carrying water or sewage in Boston .
Historical records indicate that hemlock logs were used for docking in the construction of piers along the Erie Canal in the mid 19th century. The price of timber for this project was listed at $11/1000 ft. of hemlock . The supply of these hemlock timbers was the source of mild scandal as the price quoted by the contractor for the logs ($18/1000 ft) was inflated as part of a kick-back.
In the late 19th century Midwest, timbers placed in the Cuyahoga River to create a breakwater were listed as hemlock below the water-line and the more expensive white pine above it . Hemlock logs for this project were listed as $18-21/1000 ft while white pine was listed as $26 to nearly $30/1000ft.
Appelton’s Cyclopedia of Applied Mechanics describes some of the uses of hemlock timber in constructing the Erie Canal. Foundation and apron timbers are made of hemlock while “sheet-piling is of 2-inch hemlock plant, lined with 1-inch boards. The foundationtimbers are covered with a course of 21/2-inch pine or hemlock plank” . Similarly dams were constructed of 12-inch hemlock piers .
Construction of the breakwater at Plattsburgh, NY followed a similar use of hemlock below the waterline and white pine above it . The canal at Sault St. Marie similarly used hemlock timbers both above and below the waterline. The New York Times reporting the completion of the $5,000,000 locks at Sault Ste. Marie, Michigan wrote, “From the point where the rock formation leaves off to the entrance to the power house the sides and bottom of the canal have been planked with the very best hemlock timber” .
The wood samples submitted from the Aramingo Canal project for identification are consistent with the 19th century use of wood for constructing canals.
All pieces of wood submitted for analysis were of one of two softwoods: soft pine (Pinus sp.) or hemlock (Tsuga). Hemlock was by far the more common of the two woods in the samples submitted. Both hemlock and soft pine (probably eastern white pine) were commonly used for timbers and both are described in 19th century documents as parts of canals. Hemlock, especially was used for the construction of canals and underwater portions of dams, barrages, and locks.