Note 29 — Chapter XI · A FEW MISCELLANEOUS OPERATIONS
Reading edition
The fin can be cut from sheet metal (brass or sheet-iron) and inserted in a thin saw-kerf cut exactly in the centre of the bottom, being set in thick white lead, or it can be riveted to thin plates screwed to the bottom of the boat, or lips can be bent over alternately on either side of the upper edge of the fin and screwed to the bottom.
The amount of lead required for the bulb at the bottom of the fin can be determined by loading the hull with weights until it is sunk to the water line. The weights will, of course, represent the weight of lead required. This can be cast in a mould and riveted to the bottom of the fin.