514 NICHOLLS'S SEAMANSHIP AND NAUTICAL KNOWLEDGE

METACENTRIC DIAGRAM AND CURVE OF BUOYANCY.

Sometimes, but very rarely, curves of metacentres and of centres
of buoyancy are supplied by the builder They give the heights of the
metacentre and the centre of buoyancy above the keel as calculated for
various draughts by the ship designer.

Fig. 33.

The vertical scale and the horizontal scale in the figure are equal
and represent the draught of the ship. The diagonal line KY is drawn
at an angle of 45° for convenience in plotting so that the figure K X Y Z
is a square.

The heights of the centres of buoyancy for a series of draughts
having been calculated are plotted as Bv Bz> B3, etc., and a curve,
which is almost straight, is drawn through the spots.

Thus RI BI is the V.C.B. for 5 feet draught

#2*2 » 10 „

The heights of the metacentres above the keel (K M) are also