When understanding a millsite it is important and not always simple to keep remembering that one is standing in or looking at the basement of the mill. This is where waterpower was converted into machine power by the water wheel or wheels. Water flowed to or onto the wheels and had to be carried off very quickly in the tailrace to keep them clear of back pressure, a buildup of water that slows down the wheels and reduces efficiency. Tailraces are usually long and deep to accomplish this, and in more modern applications a draft tube is attached to the bottom of a turbine to draw tailwater away.

Because of this, the identifying characteristic of a mill foundation is the opportunity for water to get out. In contrast to a house or industrial building, the foundation of a water mill will always have holes or gaps somewhere at the bottom of the walls, or even be wide open to let the water runoff. 

The earliest and most primitive sawmill foundations simply consist of two parallel walls, one with gaps or created of pillars, that straddle flowing or falling water. On top of them a post and beam mill built of huge timbers (to resist the vibration of the wheel) houses the saw itself. Essentially, this is what the North Leverett Sawmill’s foundation looks like. But that is not what we find at the Graves Ironworks.

The best way to find or interpret a millsite in the landscape is to walk upstream and start at the tailrace. The tailrace of the Graves Ironworks site runs west into the Sawmill River, right at the point where the river splits off a man-made canal to bring water to the pail shop downstream, also owned by Graves family members at various points in its existence. The water that runs through the Ironwork thus especially benefits the pail shop.

The tailrace at the Graves Ironworks appears deeply silted in, and one might walk up it for about 150 feet to enter the basement of the mill, where the turbine pits also appear to be silted in. This could be evidence of long-term use, or evidence of disastrous flooding with a lot of silt, and in any case perhaps a hint as to why the site was abandoned. 

The wheels in the foundation powered machinery that stood above the floor of the mill. Typically, one of two mechanisms was used to move the power upstairs. The older is a Pitman arm, an offset connector to a wheel that translates circular into linear motion -- such as in powering the up-and-down or sash-type saw was originally installed in the North Leverett Sawmill. 

More recently, and as currently installed in the North Leverett Sawmill, rotating power was taken directly off the wheel and carried to the machinery with a series of gears that rotated axles and ran leather belts, sometimes even from building to building. 

The Graves Ironworks employed a combination of the two technologies: it had triphammers which were likely moved by rotating power translated into linear power using a camshaft with uneven lobes on it.

Viewing the foundation from its northern edge at what may have been the floor or just below it, you can get an overview of the site with its large slabs that held the triphammers and connect the building foundation with the power canal on the upstream side and the tailrace downstream. 

Interpretation of the Graves Ironworks site is made more complicated because it bears evidence of three generations of foundations, seen as stacked fieldstone, quarried stone, and chinked and mortared quarried stone from left to right on the sign. 

Typically, water enters a mill high and exits low, to create more power in some way. However, that does not appear to be the case here, at least not from evidence still present in the foundation. On the left or eastern end of the foundation stands a wall whose construction is the oldest of the site. It seems to be an end wall of a building even beyond it. The existing stone slab conduits that, in the current configuration, lead water below this wall and into the mill at the end of the power canal may have been tailraces for an earlier mill standing on it and the walls beyond it. 

They were perhaps adapted as headraces for the later Ironworks wheels, thus bringing water into the bottom rather than the top of the mill. This suggests the shop had an undershot or horizontal wheel -- such as the proto-turbine in the patent application S.S. Graves supported in 1968, as seen on sign #8. Or the stone ducts may have been part of a way to let water pass by this shop to the next. It remains a guessing game based on tumbledown stone structures and aided by scant documentation.

And we can only imagine the wooden structures that managed the flow of water: wooden coffer dams, gates, and flumes or chutes that ran water at speed from one place to another. Levers that opened gates to start water and thus the wheels running. We don’t see or hear the complicated weaving of iron rods and gears with leather bands running up and down and back and forth that moved machinery here and in at least one other building, a turning mill. We see piles of charcoal, not the furnaces used to heat the metal before shaping it into parts for farm tools.

We must use our educated imagination to bring back that superstructure and the heat, noise, and smells that accompanied the work. And standing where the sign is positioned is a good place to start.

Written by Pleun Bouricius, Swift River Press Public History and Communications.