A gauge used to confirm the straightness of structural members. A structural member is placed between the two boards of the gauge and then rubbed. If there is no space between the gauge and the member then the member s straight. The gauge is made of a pair of straight-grained Japanese cypress, hinoki 桧, boards which are about 60-90 cm long, about 6 cm wide and have a maximum thickness of 10 mm. One example of its use is the centering of a long wooden member like a beam or log. The gauge is placed at each end of the log, and the log is thoroughly checked for any distortion. The portion with the least distortion is located, and used to center the log using a carpenter's ink pad *sumitsubo 墨壷. The jōgi is also used to ascertain the flatness of the finished material as well.
Nagatomi 永富 House owning (Hyōgo)