Tree Ring Dating

Tree-Ring Dating of The Fort- Part I

Tree-Ring Dating of the DuBois Fort in
New Paltz, New York


Edward R. Cook
Paul J. Krusic
William J. Callahan


The DuBois Fort is one of six early colonial houses owned and operated as historical house museums by the Huguenot Historical Society located in New Paltz, New York. Its construction date is thought to have been in 1705 based on the numbers 1, 7, 0, and 5 that were added to the exposed ends of iron rods used to reinforce the original four stone walls (see

Sometime after its original construction, the DuBois Fort underwent a significant expansion with the addition of a new wing to the westerly side of the house. This addition is readily apparent in the house basement, which is clearly divided into three small units that are accessed from a rear attached storage area (see the rear part of the house on the cover page, painted white and with a different roof line). The first cellar room, which is the later addition, will be referred to as the “front cellar”, through which the “middle” and “rear” cellar rooms are accessed. See Figure 1 for details. The authors of this report are not aware of any documentation concerning the construction date of the wing above the front cellar.

The supporting oak joists of the middle and rear cellar rooms are massive, squared-off oak logs with ample wany edges to sample. This style of construction is identical to that used in the Jean and Abraham Hasbrouck houses. In contrast, the oak joists used in the front cellar room are rough sawn planks that are similar in form to modern dimensioned lumber (e.g. 2×10”) used for construction today. This difference alone suggests a much more recent construction date for the addition.


Dendrochronology is the science of dating and analyzing annual growth rings in trees. Its first significant application was in the archaeological dating of the ancient Indian pueblos of the southwestern United States (Douglass 1921, 1929).

Andrew E. Douglass is considered the “father” of dendrochronology, and his numerous early publications concentrated on the application of tree-ring data for archaeological dating. Douglass established the connection between annual ring width variability and annual climate variability, which is responsible for the establishment of precisely dated wood material (Douglass 1909, 1920, 1928; Stokes and Smiley 1968; Fritts 1976; Cook and Kariukstis 1990).

Since 1921, dendrochronological methods, first developed by Douglass, have been perfected and employed throughout North America, Europe, and much of the temperate forest zones of the globe (Edwards 1982; Heikkenen and Edwards 1983; Holmes 1983; Stahie and Wolfman 1985; Krusic and Cook 2001). In Europe, where the dating of buildings and artifacts is as much a profession as a science, the history of tree-ring dating is tremendous (Baiflie 1982; Eckstein 1978; Eckstein 1984).

Over the past year, Edward R. Cook, Paul J. Krusic, and William J. Callahan visited the DuBois Fort and conducted the dendrochronological sampling that is the basis of this report. The procedures we followed were identical to those used to successfully date the Jean and Abraham Hasbrouck houses. A total of 13 cores were collected from oak joists in the three basement rooms: four in the rear, four in the middle, and five in the front cellar. All of these joists were sampled at locations with clear evidence of bark or wany edges. This is necessary to obtain the felling dates of the trees used for construction. When it was not possible to save the degraded sapwood of a given log during coring, a small wedge of wood was cut from the side of the core hole to recover the sapwood and bark edge.

Four non-joist oak samples were also collected the DuBois Fort basement. In the front cellar room, a fireplace lintel was sampled. However, it was not clear if the lintel had a wany edge. In addition, 3 oak logs lying on top of a large fireplace hearth between the rear and middle cellar rooms were sampled.

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