: SPECIAL TOOLS AND THEIR USES
This is a type of plane used for surfacing the bottom of grooves or other depressions parallel with the general surface of the work.
The planes are made in two types, one, like Fig. 281, which has a closed throat, and the other, Fig. 282, with an open throat. Both are serviceable, but the latter is preferable. These planes will level off bottoms of depression, very accurately, and the tool is not an expensive one.