deeply immersed, produces a far greater effect in stiffening the boat than would a much greater weight of iron stowed inside of her. The centre-board is generally of triangular shape. When hauled up it is contained in a water-tight trunk, or case, in the body of the boat; it works on a pivot at its fore end, and when lowered passes through the centre of the keel. When the boat strikes on a shoal, the centre-board is forced up into the trunk, and warns the steersman that it is time to go about or make for deeper water. If the centre-board is not jammed, it rarely bends or breaks when the boat runs on shore; but this does occasionally occur. It is better to employ an iron handle than a chain for hauling up the centre-board. The handle has a joint, so that it can be doubled back and be laid snugly along the top of the trunk when the centre-board is up. The advantage of the handle is that by forcing it down one can release the centre-board if the latter be jammed, as not unfrequently happens, by pebbles or bits of wood or weed that have found their way into the trunk.
The centre-board trunk occupies a good deal of space in the boat, and is often found to be much in the way. To obviate this, a folding centre-board has been invented which requires no trunk, and which the author has found to answer very well on canoes he has used on American waters. This centre-board consists of three or more plates of iron, at one end working on a pivot in the keel, and made so as to open out and close like a fan. The plates are hauled
