what is this thing?

[dowdstools]

Yep, Timber Scribe or Race Knife. I also saw a similar tool in an early 20th century catalog, that was marketed towards electricians. It seems they used them to cut grooves to lay wire into.

Lynn

[rusty]

>cut grooves to lay wire into

For electricians,  wires go in a 'raceway'....
Interesting, an old tool found a totally new use...