The tonnage time scale in use before 1886 was altered to agree with the new rating, which cannot be said to represent anything but what it really is—viz. the product of a yacht's taxable length and her sail-area.

The classification and the divisor do not alter the rule one iota. They are purely arbitrary, as was very clearly stated in an excellent letter by Mr. G. B. Thompson, published in the 'Field' of December 17, 1892. He said very truly that the 5-rating class is in reality the 30,000 class, and the 10-rating class is the 60,000 class. If the divisor 6,000 be altered alone, the result is precisely the same as altering the rating itself in like ratio, and in the same direction. Thus (R. × divisor) and (L. × S.) must each equal 120,000 in the 20-R. class, and must each equal 240,000 in the 40-R. class, and so on. In short, the Y.R.A. rule may be regarded thuswise:—In each class L. × S. = a constant, for boats at the top of the class.

By a recent decision in general meeting, Y.R.A., December 6, 1892, L. will in future be measured between the outer edges of the official marks, which must be affixed by the owner and always show clear above W.L. when a yacht lies in smooth water in racing trim.

L., therefore, is no longer L.W.L., but L.O.M. (length by owner's marks), rather longer than L.W.L.

By Rule 3, Y.R.A., in calculating a yacht's R., a fraction of or exceeding 0.01 counts as 1.0 in classes exceeding 10 R.; but in classes exceeding 1.0 R. and not exceeding 10 R., a fraction less than 0.1 counts as 0.1; and in classes not exceeding 1.0 R. fractions from 0.01 to 0.99 inclusive count for their value.

Example: 'Dacia's' certificate, June 1892, recorded S. = 887.6 and L. = 33.83 and R. = 5.00. But her S. × L. ÷ 6,000 = 5.005 and 0.005 is 'a fraction smaller than 0.1'; consequently, by the wording of Rule 3, her R. = 5.01, and she was over-rating; but the secretary, Y.R.A., when questioned, stated that the 'Y.R.A. only recognises two places of decimals,' and words to this effect were added to Rule 3 at the general meeting February 22, 1893.

The Time Allowance

The time scale for differences of R. under Rule 1. was based on the conception that a racing yacht's 'capability for speed varies as the fifth root of the rating,' the argument leading to this being that—

speed varies as √L (1)

and that sail varies as L√B (2)