“…Specialized devices are often utilized in order to record the offsets. These devices are in most cases some type of form-a-gauge (Leonard & Scheifele, 1972;Frost, 1974;Piercy, 1977;McCarthy, 1979;Green & Intakosai, 1983;Vanden Hazel, 1987;Atkinson et al, 1989). They usually consist of a horizontal bar or pipe through which vertical rods pass.…”