The "Level with Built-in Line Drawing Mechanism" is a simple improvement to the standard carpenter's level to enable easy line marking. Often when standing on a ladder, trying to hold a level still, and then attempting to scribe a line on the wall, the level slips from the force of the pencil against the level, and the result is a random (UGLY!) mark the wall.
The "Level with built-in Line Drawing Mechanism" employs a spring loaded "pencil holding block" which holds the pencil. (see illustrations) The block is then "armed" by sliding against the spring tension. Once the level has been positionsed, a button releasing the block is pressed which causes the block to move horizontally, drawing a perfect line. The "pencil holding block" which holds the pencil is also slightly spring loaded against the wall, so there is a slight pressure between the wall and the pencil independent of the pressure of the level against the wall, which ensures a visible line.
Start and stop positions of the traveling block can be set to set where the line will start and stop.