Originally Posted by
Caledonian
I agree with what has been said about the dates, but I think it is probably Victorian, i.e. not before 1837. Before that date (approximately) Wade and Butcher certainly produced a different, "concave" type, with a thin , near-flat grind transitioning into small-radius curvature near the spine, and therefore not producible with a wheel moving at right angles to the blade. I don't know how long this overlapped, in production, with true hollow-ground blades, but not, I think, by many years.