Artikel 23

Before commencing the measurement of the transverse sections it is necessary, at the positions where these sections are to be measured, to examine, if the surface to which the tonnage depths are to be taken, whether the top of ordinary floors, longitudinals, double bottom, or the top of bottom ceiling in a wooden ship, is horizontal athwartships or rises or falls from the middle plane to the wings.2) For this purpose a line is stretched across the bottom at an equal height at each side. The difference between the height of the line above the bottom at the middle plane and its height above the bottom at the sides is the fall or rise of the bottom.