217, is a marking-gage with two spurs, with which two parallel lines can be drawn at once, as in laying out mortises.

One form is made entirely of steel having, instead of spurs, discs with sharpened edges.
The _scratch-awl_, Fig.

218, has a long, slender point which is useful not only for marking lines, but for centering.
[Illustration: Fig.217.Roller Mortise-Gage.] The _auger-bit-gage_, Fig.

219, is a convenient tool for measuring the depth of holes bored, but for ordinary purposes a block of wood sawn to the proper length thru which a hole is bored, is a satisfactory substitute.
_Screw- and wire-gages_, Fig.

220, are useful in measuring the lengths and sizes of screws and wire when fitting or ordering.
The _spirit-level_, and the _plumb-line_ which it has largely replaced, are in constant use in carpentering, but are rarely needed in shopwork.
[Illustration: Fig.218.