Folks:
This is a very interesting discussion and I enjoyed reading each and every post. Based on the variety of foundations found, combined with documentary sources, you could begin to establish time periods for these foundations based on their construction technique. Portable sawmills have been around almost as long portable boilers and engines (a.k.a. Donkey engines), which first appeared during the 1840s-1850s. A review of nineteenth-century trade catalogs collected at a repository such as The Hagley Library in Delaware would likely yield numerous engravings and woodcuts of such units. Advertisements in period periodicals would also provide a similar treasure trove of information. The introduction of the circular sawblade in the 1830s made such portable mills possible, combined with the movable power source.
According to the Robert W. Lesley's 1924 work, History of the Portland Cement Industry in the United States, Pennsylvania pioneer cement manufacturers began shipping cement in barrels out of the Lehigh Valley during the mid-1870s. However, cement did not receive wide acceptance as an engineering and construction material until the 1890s and into the early 1900s. Therefore, if you find a foundation constructed with brick and/or stone assembled with mortar, the foundation possibly predates, say, 1890. On the other hand, if you find a foundation cast in cement using a wooden form, I think you are safe to date it to post-1900. Of course, these time delimiters cannot be applied uniformly, for not all mill operators would have gone to the trouble of using cement when they had brick and mortar readily available.
The other technological advancement that occurred concommitantly with the common use of cement was the internal combustion engine. Suddenly, a sawyer could use a hit-and-miss engine or other similar type of cartable engine to operate his sawmill. In time, the sawmill operator could move his portable mill around with a tractor and then use the pto on the tractor to power a pulley and drive the sawblade with a large belt. The form of the foundation can provide clues on the size of the mill as well as the source of power, based on the size, shape, and mounting rod configurations found on location.
The Pines have endured several periods where sawyers have shorn the area of most trees, beginning with complaints in the eighteenth century of timber theft due to the paucity of trees. Aerial photographs from the 1930s reveal vast stretches of treeless landscape, dotted with random columns of smoke emanating from charcoal pits--another source of tree loss. The growth we now enjoy and call "The Pinelands" is no more than 70 years old for the most part.
Jerseyman
scriptor rerum Nova Caesarea
Dei memor, gratus amicus
