When English and American rules are examined diagraphically, the sail-curves take three positions that differ considerably in their steepness--the Y.R.A. rule giving a curve nearest to the horizontal which indicates R. = S. ÷ constant, proposed by Mr. Richardson in 1886 (or R. = [V¯]S ÷ constant if expressed in American measure; or R. = S. [V¯]S divided by a constant if expressed in English measure); and the New York rule taking a position nearest to the vertical denoting R. = L., under which the Solent Length Classes used to sail. The Seawanhaka rule gives an intermediate curve--perhaps the 'happy medium.' The curves have been plotted for yachts of 40-rating by our rule, and the following table gives the actual numbers:-- +---------------------------------------------------------------------+ | | Sail-area allowed to | | +------------------------+------------------+-----------------+ |L.W.L. | 40-raters, Y.R.A. Rule | 61.5 Corrected L.| 61 Corrected L. | | | | Seawanhaka Rule | New York Rule | +-------+------------------------+------------------+-----------------+ | ft. | ft. | ft. | ft. | | | | | | | 54 | 4,444 | 4,761 | -- | | 56 | 4,286 | 4,489 | 5,041 | | 58 | 4,139 | 4,225 | -- | | 59 | 4,068 | 4,096 | 4,096 | | 60 | 4,000 | 3,969 | -- | | 62 | 3,871 | 3,721 | 3,481 | | 64 | 3,750 | 3,481 | -- | +-------+------------------------+------------------+-----------------+ _The Turning-point of Maximum Efficiency, or best Length_