Christopher Schwarz wrote:

>Joseph Moxon describes this cheek-paring technique in the Mechanick
>Exercises chapter on joinery. The mortise he is describing being made
>in this manner is enormous -- he's using an 1"-wide mortise chisel.
>But other later authors discussing cabinet work (from Hayward to
>Holtzapffel) favor a chisel that is the same width as the resulting
>mortise.
>

I think it is possible to read too much into this. Moxon mentions
using a narrow paring chisel to clean/square the ends of the
mortise, followed by:

      "... Then with the broad Paring-chissel, pare the sides of the
    Mortess just to the struck Lines ... "

However, in discussing the layout of the mortise and tenon joinery,
he mentions that the material is "four inches broad," then instructs
to " ... set the Oval [head] of the Gage an Inch and an half off the
Tooth ...," and to strike the mortise/tenon lines by gaging off both
faces of the stuff. Other than the fact I think gaging off both faces
is poor practice, the outcome of this approach is to leave a nominal
dimension of one inch between the two gage lines. Which is quite
consistent with his instruction to use a one inch mortise chisel to
chop the mortise.

So, it is not clear to me that Moxon is advocating the use of an
"undersized" mortise chisel. Rather, he may simply be describing a
little light paring for final clean-up. Final clean-up, possibly
necessitated, in part, by gaging off both faces. In short, his
approach may not differ all that much from later writers and my
own preference.

I agree with Chris that such paring is problematic, but, occasionally,
situations arise which require some clean-up of the cheeks of
mortises. C. F. Partington, writing in 1825 (_The Builder's Complete
Guide_, suggests an alternative approach which people might find
useful:

      "It is of the utmost importance in framing, that the tenons and
mortises should be truly made. After a mortise has been made with the
mortise chisel, it should be rendered perfectly even with a float;
an instrument which differs from a single cut, or float file, only by
having larger teeth [which are soft enough to be sharpened with a
file]. ... ."

Don McConnell
Eureka Springs, AR

------------------------------------------------------------------------