The try-square is also of great use in scribing lines across boards, Fig.204.A good method is to put the point of the knife at the beginning of the desired line, slide the square, along until it touches the knife-edge; then, resting the head of the square firmly against the edge, draw the knife along, pressing it lightly against the blade, holding it perpendicularly.

To prevent the knife from running away from the blade of the try-square, turn its edge slightly towards the blade.
The _miter-square_, Fig.

201, is a try-square fixed at an angle of 45 deg.
The _sliding T bevel_, Fig.

202, has a blade adjustable to any angle.
It may be set either from a sample line, drawn on the wood, from a given line on a protractor, from drawing triangles, from the graduations on a framing square, or in other ways.

It is used similarly to the T-square.
[Illustration: Fig.205.