public Number getWindDirection(int series, int item);

    /**
     * Returns the wind force on the Beaufort scale (0 to 12).  See:
     * <p>
     * http://en.wikipedia.org/wiki/Beaufort_scale
     * 
     * @param series  the series (in the range <code>0</code> to 
     *     <code>getSeriesCount() - 1</code>).
     * @param item  the item (in the range <code>0</code> to 
     *     <code>getItemCount(series) - 1</code>).
     *     
     * @return The wind force.
     */
    public Number getWindForce(int series, int item);