The excavation at the Carome Mill was successful and I think has answered the main questions I posed in relation to the type and phases of technology employed in this early watermill. The foundations of Seargentson's original 1841 mill building could be identified along with alterations from the 1858 rebuilding by William Hardesty and Abraham Willis. This showed that the original very simple timber pit wheel and pinion gearing for a single set of stones had been most likely replaced by iron bevel drive from the water wheel to a ‘great spur wheel’ driving two stone nuts. This is what I suspected from historical sources and comparisons with pre- and post- improvement mills in Britain. It also fits with what is known about the capacity of the Fulton Foundry to manufacture relatively large cast iron gears. The water wheel was also enlarged and shifted as the building appears to have been extended to the east.
The changes can be seen in the two 19th century illustrations of the mill. In the first from 1849, the building has a single storey and loft with the water wheel contained in a substantial squared stone wall.
In about 1858, the building had been raised with an upper timber floor added, and a separate stone pillar construction supports the outer end of the water wheel shaft. The water wheel is larger and now extends to near the top of the stonework.
The photo below is looking down from the rock escarpment on the north side of the Carome Mill site on 30 March. The 1841 structure can be identified by separate areas of mud mortar and shell lime mortar. Most of the 1858 additions were removed, but the 1841 pit wheel slot and water wheel pit have been filled in with stone set in slaked lime mortar, which would not have been available until after the gold rushes. This would have been done in 1858 when the mill was enlarged, and intended to prepare the base for supporting new machinery. I only excavated a small trench across the water wall, where the shaft of the water wheel would have entered the building through the external wall, and the gearing would have been just inside. The other external walls are mostly identifiable from footings and the retaining walls built into the hillside excavation. The site has now been backfilled.
The historical and archaeological evidence indicates the mill was altered from a fairly typical 'Vitruvian' form of technology, to an improved design. This reflected the change that occurred in Britain around the beginning of the 19th century, when the simple Medieval form of timber geared milles with a single set of mill stones, were being replaced with or upgraded to a more efficient and productive technology which employed more complex cast iron gears designed to drive multiple sets of mill stones as well as other grain cleaning and flour dressing machinery.
Probable 1841 arrangement of gearing
Probable 1858 arrangement of gearing
