paul womack wrote:
> I'm afraid my digital camera is broken, so I have prepared
> a diagram here:
> http://www.wdynamic.com/galoots/4images/details.php?image_id 

I wrote of my hasty observations and guesses
of blades in my possession.

As it transpires, my first diagram was not very accurate,
but what I wrote/drew were enough to strike
a chord with the remarkable old tool knowledge
of Don McConnell.

He remembered a process that was a remarkably good fit
with what I'd presented, and went off to his library.

He found...

"A Treatise on Files and Rasps", published by the
Nicholson File Co., Providence, RI, 1878.

In it the following illustration:
http://www.wdynamic.com/galoots/4images/details.php?image_id=4563

Which is a remarkably good match with my second, more careful,
diagram of a toothing plane blade.
http://www.wdynamic.com/galoots/4images/details.php?image_id=4553

Don quoted text from the pamphlet as follows:

"In cutting files by hand, the operator is seated before an
anvil of special construction, which is mounted on a block;
the [file] blank to be operated upon, is, by means of the
feet, held down to the anvil by two leather straps, the
tang end of the blank being toward the operator. Wth a
chisel in one hand, held at the proper angles, and a hammer
of peculiar shape, in the other, he strikes his first blow
upon the chisel, which is placed at the point of the file;
this throws up a barb or ridge, extending across its surface.

    "The chisel is then replaced on the blank, and is slid
up until it encounters the barb already made, when the second
blow is given, and so on, until the first course of teeth
is completed, so far as this face of the file is concerned."

Summary;
In conjunction with my observations of my blades,
it appears that we now have very good circumstantial
evidence to claim that we know how toothing blades
were made.

This may be genuine "reclaimed" lost knowledge

   BugBear
------------------------------------------------------------------------