HEMLOCK---THE SECRET INGREDIENT THAT MADE IT ALL WORK

          Unity would have never had a tannery on Sandy Stream if there were not an abundance of hemlock. At the time the tannery was established, Unity was mostly cleared land; under the axes of the farmers, most of the forests had disappeared like melting snow. But not the hemlock woods. If the hemlock had been equivalent to pine as a lumber source, there would have been none standing by the time tanneries came to New England. However, the available hemlock forests  in the 1820s were the one single resource that provided enough to support the tannery, pay its sizeable labor force, give farmers and loggers a new source of income, and  send Waldo County leather around the world.

            Sebago Lake formed the heart of hemlock country, a strip about sixty by two hundred miles in size. The Eastern hemlock (Tsuga canadensis) has still always been an important tree of the forest ecosystem in Maine, connected to the well-being of other species of trees and animals. It is a slow growing species  that grows in moist, shaded forests. Its roots prefer shallower soils with ample drainage. Young hemlocks rely on forest canopy to filter sunlight and allow for slow growth. A seedling hemlock can bide its time for over seventy years as a tiny sapling and then shoot up when an opening in the canopy presents itself.  Saplings cannot survive in open areas with direct sunlight; in fact, it is the most successful North American tree in tolerating deep shade. Undisturbed, a hemlock can grow for as many as 900 years— probably the longest lived tree in the northern woods— and reach heights of sixty to seventy feet. Several species of animals, such as deer and many birds, feed on young hemlock. Although it is a dominant species in the forest, it frequently shares acreage with deciduous trees such as yellow birch, sugar maple, white pine, balsam fir, and red spruce.

        Hemlock eventually became essential for the  tannery, but not right away.. It took a long time for hemlock to get any respect at all.  For the first centuries of settlement, it was Eastern white pine that was the king of the Maine landscape. These huge pines had diameters of more than six feet and heights of over two hundred feet. Because the white pine provided wood that was light colored and easily worked, it was highly desirable for lumber. This tree started the entire lumber industry of Maine, and for years it was the only species harvested. It was not until the mid-1800’s that spruce, a more northern species, was harvested in the state. Spruce later became the primary choice of loggers, as the resource of white pine was almost near depletion. Spruce is still the mainstay of the paper pulp industry.

        In the earliest years of European settlement, hemlock was of no market value because of its harshness and uneven, coarse grain. The wood is extremely susceptible to ring shake, warping, and checking. Hemlock is also difficult to thoroughly dry. Compared to pine and spruce, hemlock is far less desirable for lumber. Once the mid-coastal Maine forests were barren of quality timber, one of the few species that remained was the Eastern hemlock. Hemlock could be found throughout the state but was best suited to the southern soils.

          So what was the secret of hemlock’s success? In ancient Egypt it was discovered that the bark of trees could be ground up and used in solution to tan hides. In the 1800’s, Europeans used the bark of oak and sumac to tan hides, but the colonists soon discovered that hemlock bark could be employed just as well, and without staining the original color of the hide as oak does.. Eastern hemlock bark contains 10-13% by weight of tannin, the primary chemical in the tanning process (and the same chemical that makes tea look tea-colored). The tannin makes it extremely rot resistant, sometimes for over fifty years. In fact, you can tell that an old stump is a hemlock because the ring of bark stays more or less intact even after the wood inside has turned to crumbly brown duff.

          As a result of its tannin, hemlock bark quickly became a staple in the Maine tanning industry.  Not surprisingly, the heart of hemlock country is closely congruent to the area in which most tanneries existed in Maine between 1830 and 1860. Unity had the advantage of being in the center of the hemlock country. The Unity forest in the 1850s contained about 20-27% hemlock, which was enough to support more than one tannery.

     To obtain the tannin, hemlock logs had to be stripped of their bark during sap season, from early May to late June. Teams of men would search local forests for valued bark. They had to work fast because the harvest season was short and the demand for tannin was high. In the early years, the bark was stripped and taken to the tanneries while the standing dead tree was left to rot. The logs provided homes for many insects and food for insectivores, but did little for the rest of the ecosystem. Without bark, the flow of water and nutrients was disturbed and the trees would die, leaving whole hilltops with a silvery hue when seen from a distance. Occasionally, leftover hemlock logs were used for “paving” rough sections of road, such as depressions, ruts, and potholes (Connor). In later years, when lumber was even more scarce, standing dead  hemlock logs were salvaged for posts and beams.

       The tanning industry soon became second only to Maine’s lumber industry as a source of wealth from manufacturing..  It was responsible for providing many jobs both in the forest and in the tanneries. In 1872 there were a total of nineteen tanneries operating in the state that used a total of 110,000 cords of bark yearly to produce 11,000 tons of leather.  The Unity tannery, at its height, used up to 2,500 cords of bark annually. This is an astonishing figure! (320,000 cubic feet or 11,852 cubic yards a year….)    Not only did the tannery need a huge supply of bark, it also needed firewood for steam power in the processing of hides. Vickery reports that the tannery burned up to 1,200 cords of wood for this purpose. Considering the tremendous demand for these products, one can infer that the tanning industry had a significant impact on nearby forests.