| 摘要 |
A square with longitudinal slots in the angular arms, a rule having a longitudinal slot, and two clamping screws for securing the rule in various angular positions on the arms of the square, so that the scale may be shifted on the square to establish a number of angles, and be maintained at its adjusted position. Spirit levels are provided on each of the square arms and on the rule. The square arms and rule are thick thereby providing saw guides. The square arms are each marked with measuring scales as well as with markers for twelve inch or sixteen inch center layouts. The rule is marked with a plurality of degrees for common pitch lines and hip and valley pitch lines.
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