My good friend Chris How MSc. from Victoria, Australia sent me the following email extract this week which rather nicely helps put circular saw dating criteria into perspective -
"Thanks for the news Ken, and the reference from the Timber Framers Guild. The US probably mimics Australian experience with respect to having constantly moving frontiers. There is a claim by the Shakers in America that Sister Tabitha Babbitt invented the circular saw in 1810 at Harvard. The first British Patent was in 1777 by Samuel Miller in Southampton and it was perfected by Sir Marc Brunel and Bentham for use in Portsmouth Dockyard in 1809, however it is believed that Robert Hooke invented a small circular saw for the manufacture of scientific instruments in the 1670s.
The real problem was one of portable power, which was not solved till the advent of steam engines in 1805, but these were not widely available until the 1840s. In Australia, the ideas were known but there were no roads & very little infrastructure, so the engines that were imported came in by sea to places like Port Fairy, where they could be lifted onto a wharf. Last week I measured an 1849 Port Fairy cottage floor joist which had been conversted using a 2 feet dia circ saw. Table 4 on p46 of my dissertation is not as conclusive as I had previously thought, but that more powerful engines could drive larger dia blades, however these could not be moved far. The 16 inch blades that I previously found must have still been in use for some time after, and like the item says, used for making laths & battens. You may be interested to note that Scotsmen were the most advanced or far sighted in respect of employing portable engines here in Victoria. Labour was difficult & expensive up to the 1880 depression. Roger Champion (Weald & Downland museum carpenter - now retired) told me that pit sawing was still practiced in Sussex in 1930, & this practice is also mentioned in "The Village Carpenter" of course. So to get early circ saws marks you need expensive labour and good infrastructure. It varies obviously from place to place in Australia and so there may be no hard and fast rule."
The Australian experience might not be exactly the same as New England but Chris raises many good points especially with respect to Power / saw blade diameter / infrastructure / and rather surprisingly Scotsmen of which I am one ! Having been brought up and attended university in Glasgow near the birth place of the modern steam engine I am not surprised by Chris How's proposal that the link between that country and New England building practice might lie more with timber conversion related issues.
This forum thread has demonstrated the value of taking advantage of international joined up thinking to help solve local problems.
