Derek Cohen (in Perth, Australia)
Hi Warren

The specifications noted on the Seaton planes only indicate what was in that toolbox. While I'd like to believe that they knew what they were doing with plane design, progress happens. For example, steel planes came later (although one might debate whether these were advancements ).

A few questions of my own:

1. Is there a body of historic literature on mouth size available similar to that on chip breaker use?

2. Assuming that it is easier/more reliable to build steel planes with small mouths, would this have accounted for the larger mouths in the Seaton chest? That is, smaller mouths became a feature of improved chip control as manufacturing techniques changed. If so, what are the specifications for Spier and Norris infills?

3. What research has been done on mouth size (as opposed to anecdotal reports)? There is the assumption (based on logic?) that a smaller mouth facilitates better chip control. Is this fact or fiction?

Regards from Perth

Derek