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United Kingdom (Types have evolved according)

and types have evolved according to the different formulæ from time to time adopted. There are four principles upon one or more of which any and every rating rule must be founded. First, tax motive power-that is sail, and leave the designer a perfectly free hand in respect of displacement, that is to say weight, and of form. Secondly, tax displacement, and put no restrictions upon form or motive power.

Thirdly, tax dimensions, and leave displacement and motive power alone. Fourthly, tax both dimensions and motive power. The last principle has been adopted with various modifications, since the introduction of the length and sail area rule.

The first two propositions possess the merit of simplicity. To tax sail area alone as the measure of size for racing purposes, and to ordain that vessels carrying a certain number of square feet of canvas should be classed as of so many tons, would be an easy and simple method of classification, and it would seem at first sight as though in the course of time the most perfect type of hull must by such a rule be evolved. Designers, being restricted in a certain class to a given number of square feet of sail area, would gradually discover the form of body which would be most easily moved by the power derived by the wind acting upon that area of canvas; and very likely such a result would be arrived at through the operation of the law of the survival of the fittest. But evolution would be attended by considerable loss of life, quite incompatible with ordinary ideas of legitimate sport. Displacement and natural stability, that is, stability deduced from breadth, would be reduced and reduced, until vessels became dangerously over-canvased and over-sparred.

The tendency of such a rule would be to reduce displacement, strength, and stability to a minimum.

Of course, other considerations would act as a check. Racing yachts from 50 tons upwards have to voyage round our stormy coasts from the Thames to the Clyde, from the Clyde to Ireland, back to the Solent, and down the west to Falmouth, in the routine of a regatta season; they must be capable of making passages in any ordinary weather, and sometimes in very extraordinary weather, and they must have sufficient stability to stand up to their canvas under average conditions of wind. But the check would be insufficient: men become very reckless in racing. It is an historical fact that the Largs Club on the Clyde made it a rule that the hands sailing in their class of open lug sail boats should wear cork jackets, as capsizes were not infrequent. But they had to discontinue the rule, as it was found that the men filled their jackets with shot instead of cork, in order that by sitting up to windward, and acting as shifting ballast, they might give their boats an advantage when sailing on a wind.

It would not do, therefore, to rely upon the self-preservative instincts to prevent vessels from being built unduly weak, or becoming dangerously over-canvased and over-sparred. The converse rule of taxing displacement, or taxing displacement and dimensions, and leaving motive power -that is, sail area-free, would obviously produce precisely similar effects, and for similar reasons it is objectionable. Hence it follows that framers of rating rules have been driven to adopt the last alternative, and to tax both dimensions and sail. Naval scientists have never been able to propound a definite and satisfactory rule as to the true basis for measurement of tonnage, or rating of yachts in competitive sailing. The various formulæ from time to time employed are purely empirical. They are not, and probably cannot be, based on any simple principle, but are of the nature of a compromise, consisting of the taxation of motive power, and of one or more of the principal dimensions; and they have been altered and modified from time to time to meet the various objectionable characteristics in the type of vessel produced under them.

How far they have been successful is a matter for argument, but one thing is quite certain: they are all exceedingly imperfect, and it still remains for some genius to hit upon an ideal rating rule.

Without going deeply into the mysteries of yacht designing it is evident that the gradual pressure brought to bear by designers upon the weak points of the rules of measurement in their efforts to reach perfection in speed has been the primary cause of the principal changes in the construction and form of racing craft during the past thirty years. As the weak points in the several methods of measuring "tonnage" or "rating" are detected or supposed to be detected by the critics, an inevitable cry for some change in the rating rule follows, and the alteration, when made, has usually brought about a considerable change in the form of the racing yacht.

But it must not be supposed that the change has always been for the better, or that the desire for change was evinced by yacht owners and practical men. vary the points from which the measurements are taken to meet the necessity of the case in such vessels. This gives the committee a free hand to keep to the true meaning of the law and demand scantlings proportionate to the size of the vessel classed, whatever her shape or style, and for this reason the "tonnage cheater" before the vigilant eye of Lloyd's Register is reduced to a nonentity.

The measurement of yachts for racing, however, is the branch of the subject which has more interest for the majority of yachtsmen of the present day, and this leads us to look to the era of builder's and Thames measurements and to find why these methods eventually came to be deserted.

The true value of sail area as a natural factor in the measurement of yachts for racing was not realised by the experts until a later date, but apart from this point, in which all rules that did not tax the "driving power" were equally weak, the Thames measurement was considered unsatisfactory, inasmuch as it encouraged the develop- MM "CORSAIR," "METEOR,, "AILSA, "ISOLDE, "SATANITA.

During the past sixty years the measurement rules have undergone rundamental alteration, and new rules have come into force, in the years 1854, 1881, 1887, 1896, 1901, and 1907. Prior to the year 1854 several methods were adopted for finding the tonnage. The original system of measurement was to multiply length, breadth, and depth of hold and divide the result by 96-the figure 95 being chosen because it produced a result approximate to the tons burthen the vessel could carry. 94 was subsequently substituted for 06.

This method, which was used for ascertaining (for purposes of assessment) the registered tonnage of all British vessels, was subsequently altered to the present system of assessment upon the actual cubic contents of the vessel. Lloyd's, while recognising registered tonnage for calculating the weight of outfit necessary for yachts built under their survey, determined the scantling by a numeral ascertained by adding together breadth, depth, and girth, and multiplying the sum by length. As regards yachts, the first change consisted of the introduction of what is known as builder's measurement, in the place of the beforementioned rule. Builder's measurement, or as it is sometimes called old measurement, is usually signified by the symbols (BM) or (OM) and is found as follows: (length-breadth) x breadth × breadth divided by 94 tonnage. This method is still used by builders in finding the tonnage of yachts.

In the year 1854 "Thames" measurement with the following formula (length-breadth) × breadth × breadth divided by 94 tonnage was introduced. The length was measured from the fore part of the stem to the after part of the stern post in a straight line along the deck.

In taking measurements for scantling, the committee of Lloyd's Register make a proviso as to yachts of peculiar construction, so that they may ment of yachts of too small beam in proportion to their length. 66 For many years during which the rule had been in force this tendency was slow in its development because designers had not learned to adopt the use of outside ballast, and consequently had to rely upon beam for stability. Prior to the year 1870, no yacht had been built with more than ten per cent. of her ballast on the keel. In 1871 Peg Woffington," of eight tons, carried all her ballast in the shape of an iron keel. During the next few years experiments were made in the smaller yachts with outside lead ballast, which proved so successful that lead keels bolted on outside were fitted to larger craft, and the advantage of decreasing breadth and making good the loss of stability, without increasing displacement, by lowering the centre of gravity was proved.

The method of measuring the length between stem and stern post was also found to be unsatisfactory, as it produced long immersed counters; and one of the first moves of the Yacht Racing Association, which had been founded in 1875, and had adopted the "Thames" rule as its code of measurement, was to alter the mode of finding length in favour of the present method of measurement, namely, on the load water line.

This alteration was made in 1879, and two years later, in 1881, the formula for finding the tonnage was altered to (Length + Breadth)2 x Breadth This rule, known as the 1730 rule, which was in force until the year 1886, saw the sport at its height amongst the classes of 40 tons and upwards, of 20 tons, IO tons, 5 tons, and 3 tons; but, curiously enough, its effect was exactly the reverse of the intention of its authors. It was meant to increase the proportion of beam to length; it succeeded in decreasing it. In each successive year yachts in all classes became longer, narrower, and deeper, and in the classes below ten tons the "plank-on-edge" craze was at its worst.

Yachts of composite construction became general under this rule, the increasing weight of lead keel that year by year the craft were called upon to carry popularising the use of steel frames and the heavy internal T iron keels or foundation plates. However, the doom of the narrow type was effectually sealed for large and small yachts alike in 1886, when the Yacht Racing Association went into the matter of the measurement rule, and in an exhaustive report, arrived at after consultation with many eminent yacht designers, decided that the tonnage rule, which had been in force since 1881, was unsatisfactory, and recommended another. The change was a new departure, and consisted in linking hull and sails together by the following formula :- Length x Sail area in square feet 6000 The idea was by no means a new one, having been under consideration in this country in 1880, and adopted by the Americans in 1882. In fact, it may be said that British yachtsmen proved to have been six years behind the times in adopting their own formula. Be that as it may, the Yacht Racing Association set to work and revised the "Classes" as follows:- The new 60 rating and above in place of 40-tonners and above. دو دو وو وو 40 raters for 20-tonners. 20-raters for IO-tonners.

IO-raters for 5-tonners. 5-raters for 3-tonners.

And after some discussion a sixth class was admitted for 2-raters In 1887 this style of measurement came into force, and continued law until 1895.

It is evident from the records of yacht racing that from the date of the framing of the length and sail area rule the pastime in all its branches attained a popularity far beyond the expectations of its most ardent supporters, and as far as can be gathered from records and correspondence, yacht owners, after six years' experience of this code of measurement, were for the most part satisfied with the type of craft which the rule had developed. 66 Nevertheless, builders and designers, supported by the inevitable crowd of theorists," whose pockets were literally bulging with rating rules of every conceivable kind and character, the accumulation of a six years' peace, were ready to declare war against the length and sail area code of measurement.

Their chief argument against the rule was that it tended, especially in the classes of 40 rating and under, to the production of vessels with small under-water body, and poor internal accommodation unfit for any purpose but racing. No immediate action was taken until August 1894, when the subject was brought before the Council of the Yacht Racing Association at Ryde.

After nine months' consideration, a conference of the Yacht Racing Association Council and certain experts and designers brought forth the first linear rating rule, and recommended that the formula be altered to 2 Length + Beam +0.75 Girth+0.5 Sail area Linear Rating and that the new rating lengths be arranged as follows, to correspond with the former class ratings:- Linear Rating. وو Old Rating. rating 12 وو دو 18 feet 24 I 30 2 وو 36 5 ور 42,, 10 20 40 52 65 وو دو وه وو وو The rule was finally passed by the members of the Yacht Racing Association in July, 1895, and came into force in the season of 1896, with a subsequent provision that no change should be made for another three years.

It will be seen at a glance that the principal point in which the linear rating formula differed from the preceding rule was in the introduction of a girth measurement. This measurement was taken round the skin of the vessel from water line to water line, technically round the vertical cross section, at a distance 06 from the point where the stem cuts the water. If the draught forward of this point, not including the girth of a bulb, if any, exceeded the draught at that station, twice any such excess was added to the girth.

Centre-boards or plates, whether fitted with bulbs, or ballasted, or otherwise, were measured as fixed keels.

It was feared by some that the practical difficulties in the way of measuring girth would tend to make the sport unpopular, but such does not appear to have been the case, for practically no decrease either in the number of yachts built or of matches sailed was apparent. The advisability of adopting a different code of measurement for large and small classes was considered, but was wisely abandoned, in the hope that at some future time an international rule might be adopted for yacht measurement, under which yachts of any country might compete in any waters without serious disadvantage.

The alteration in the measurement formula did not make any appreciable difference in the type of vessel, and racing yachts built under the first linear rating rule still lacked adequate accommodation below decks. In view of the heavy cost of construction of large racing craft, it was felt that such yachts should be capable of affording comfortable living accommodation for the owner and his friends, and in the year 1901 was introduced a new rule expressly designed to encourage habitability in racing vessels.

The formula of this second linear rating rule was as follows :- Where L+B+0.75 G+4d+5/s 21 L=Length on water-line in feet.

B-Extreme breadth in feet.

G=Under-water chain girth at ob of L from its fore end in feet. d-Difference between G. and the underwater skin girth taken at the same point in feet.

S=Sail area in square feet.

The only points of difference between this rule and its predecessor were the inclusion of the d factor and a slight modification of the divisor, but the vessels produced under it were of quite a different type. By taking two girth measurements, one round the skin of the yacht, and the other by means of a chain stretched tightly under the keel, and measuring the difference, hollow in the midship section was heavily taxed, a feature that encouraged large displacement. The result was a fine, roomy craft with splendid internal accommodation, and, save for one or two minor defects, the type was all that could be desired.

The worst feature of the yachts built under the rule, so far as shape was concerned, was the long flat overhangs which slammed in a rough sea, and were a source of weakness. Although such vessels took very little green water on board, they could hardly be termed dry boats, as the flat pram bows smashed the tops of the seas when the yacht was beating to windward, and sent aft a continuous shower of blinding spindrift which soon found its way through the best of oilskins.

With length, beam, girth, girth difference and sail area penalised, there was not much scope left for the exercise of ingenuity in the way of "rule cheating" on the part of designers, who soon turned their attention to the saving of weight in construction. Every pound of weight filched from a racing-yacht's hull leaves a margin for an increase in sail and ballast, and this weight-saving policy was carried to extremes.

With designers contending with one another in the matter of light construction, the limit of safety was soon passed, and leaky vessels were the result. As an instance of the flimsiness of the racing yachts of that period may be cited the case of a 52-footer which started her bow planking by merely pitching into a short head sea whilst beating to windward in the mouth of the Medway.

The position was now somewhat anomalous.

The Yacht Racing Association had evolved a yacht affording great habitability which was yet uninhabitable owing to her leaking propensities.

After a season or two's racing such a craft was only fit for the scrap-heap, and could be sold for little more than a breaking-up price. Outclassed for racing and useless for cruising purposes, nobody wanted her, and she was a drug on the market. Under these conditions first-class racing ceased to exist, and yachtsmen built "fast cruisers" and sailed them in the handicap classes.

Owners declined to sink large sums of money in the construction of big cutters that might be useless after a season's racing, and the measurement rule had been in force for six years before Mr. Robert W. N. Young built the first-class cutter Nyria," which, however, he had planked with teak and constructed to Lloyd's highest cruising class. The success of this yacht when pitted against the Fife-designed "White Heather I." and the Watson cutter "Kariad," served to explode the old theory that it was impossible to combine the best racing and cruising qualities in one vessel, and paved the way for the scantling restrictions which were subsequently introduced. 66 Towards the end of 1905 the Yacht Racing Association issued an invitation to the legislative bodies of other countries interested in yachting to attend an International Conference with a view to the adoption by all nations of a uniform code of rules. At that time each country had its own measurement formula and sailing regulations, a state of affairs that was inimical to international sport. Under such conditions a yacht competing in foreign waters had to undergo the vexatious formality of remeasurement under a rule to which she had not been built. She consequently laboured under an enormous disadvantage, for what might be regarded in her own country as desirable features in her design might be heavily taxed under a foreign rule. a Then, again, there was a considerable divergence in the sailing regulations that obtained in different countries, and the skipper of a visiting yacht had to sail under a code of rules with which he was unfamiliar. These obstacles were of such serious nature that yachtsmen were deterred from engaging in friendly rivalry with sportsmen of other countries, and, save for an occasional contest for the America Cup, international yacht racing was practically non-existent. But the sport of yacht racing had for some years past been making rapid strides on the Continent, and the time was ripe for the consolidation of the various rules into one common code.

The invitation of the Yacht Racing Association met with a ready response, and when the Con- 'NYRIA" RACING AT COWES. ference met in London under the presidency of the King, then Prince of Wales, on January 15th, 1906, eleven countries were represented by the following delegates: Austria, Lieut. Baron von Preuschen; Denmark, Messrs. F. Hegel and Alfred Benzon; United Kingdom, Messrs. R. E.

Froude and W. P. Burton; France, Messrs. Louis Dyévre and Blanchy; Germany, Messrs. Burmester and Busley; Holland and Belgium, Messrs. W. Six and M. Von Bernuth; Italy, Count Eugene Brunetta d'Usseaux; Norway, Mr. John Anker; Sweden, Rear-Admiral Jacob Hagg and Mr. Theodore Alpen; Switzerland, Mr. Jean Miraband. The following naval architects and experts were also present: Mr. William Fife, Mr. Alfred Mylne, Mr. Soper, Mr. C. E. Nicholson, Mr. Anderson (Sweden), and Mr. Ljungberg (Sweden). It will be seen that all the principal yachting countries of the world were represented with the exception of the United States of America. The New York Yacht Club, as the chief yachting organisation of the States, had appointed two delegates to attend the Conference, and although these gentlemen had actually booked their passages, they were recalled by the Club at the eleventh hour.

Under the chairmanship of the late Mr.

Augustus Manning, senior vice-president of the metres or 164 feet.

Yacht Racing Association, the Conference sat for four days. The task of reconciling so many opinions and formulating a common rating rule was a herculean one, but all present were actuated by an earnest desire to come to an agreement.

Step by step the new formula was built up, until, finally, the International Rule of Measurement sprang into life, the formula recommended for adoption being as follows:- 9 IO I2 15 19 23 وو دو دو دو وو دو دو وو وو دو دو وو دو دو وو دو دو وو 29 5 328 39.4 49 2 62 3 75 4 دو دو دو وو وو وو وو وو دو Rating in linear units, i.e., either feet or metres.

Where 2 L=Length in linear units.

B-Beam in linear units.

G=Girth in linear units. d-Girth difference in linear units.

S=Sail area in square units.

F-Freeboard in linear units.

Length. The length, L, for the formula is to be the length on the water-line, with the addition (1) of the difference between the girth, covering-board to covering-board, at the bow water-line ending, and twice the freeboard at that point, and (2) one-fifth of the difference between the girth, covering-board to covering-board, at the stern water-line ending, and twice the freeboard at that point. Beam. The beam, B, is to be taken from outside to outside of the planking, at the broadest place, including wales, doubling planks, and mouldings of any kind.

Girth. The girth, G, is to be the chain girth, measured from the upper side of the coveringboard, round the keel, to the upper side of the covering-board again, at that part of the yacht at which the measurement is greatest, less twice the freeboard at the same station. This station is to be indicated on the covering-board by an official mark [G]. Should the chain girth be the same at several stations, that which is nearest to the greatest beam shall be adopted for subsequent measurements. But if the keel underside line abaft the girth station is straight except for a reasonable round at the extreme after end, the station for the girth measurement may be fixed by the designer anywhere abaft 055 L.W.L. length from its fore end, provided that the maximum chain girth, covering-board to covering-board, does not exceed that at the station so fixed, anywhere forward of that station, or by more than 3 per cent. anywhere abaft of that station.

Should there be any hollow in the fore and aft under-water profile, the girth and difference measurements shall be taken under an imaginary keel line, excluding such hollow.

Girth Difference. - The girth difference, d, in the formula, is to be the difference between the chain girth, measured, as above described, from covering-board to covering-board, and the skin girth between the same points, measured along the actual outline of the cross-section.

Sail Area. The sail area, S, is to be measured as stated in the Y.R.A. rules. The spars are to be marked with black bands, as in the American rules.

Freeboard. The freeboard for the formula is to be twice the freeboard at the girth station, plus once the freeboard measured at the bow water-line ending for length measurement (see above), plus once the freeboard measured at the stern water-line ending, the sum to be divided by four.

Crew. All measurements to be taken without crew on board.

The international rating classes agreed upon at the Conference were the following :- The A class (for schooners, yawls, ketches, and luggers) above 23 metres.

Although the international rating rule does not show any great departure in general principle from the 1901 formula of the Y.R.A., the modifications introduced were expressly devised to eliminate certain undesirable features noticeable in yachts built under the latter rule. The addition of the overhang flare to the water-line measurement was intended to check the construction of vessels with excessively long and flat extremities, whilst a premium was placed upon freeboard to encourage a boat with a bold topside, a feature that makes for head room below decks, and dryness in the seaway. The reduction of the impost placed upon girth difference was the result of experience gained under the 1901 rule, 4d. having been found too harsh a tax upon hollow sections. The greatest innovation, however, was the adoption of scantling restrictions, it being ordained that all racing yachts should be built under the supervision and to the scantling rules of the English or German Lloyds, or the according to the materials used in construction.

Bureau Veritas, and classed for a term of years It was also decided to prohibit the use of hollow masts in all classes above IO metres rating.

After the legislative bodies of the countries interested had had time to digest the somewhat complicated formula, a second Conference was held in London on June 12th, 1906, when the International Rating Rule was formally adopted and fixed for a term of ten years commencing on January 1st, 1908. At the same time a permanent committee of referees was appointed to deal with any disputes that might arise as to the interpretation of the rules. This committee was composed of the vice-president of the Yacht Racing Association (chairman), Mr. Benzon, M. Le Bret, Professor Busley, and Professor Froude, with Mr. Brooke Heckstall-Smith secretary. as As class racing had fallen to a very low ebb in this country, it was decided to anticipate the official date fixed for the introduction of the International Rules, and the classes of 23, 15, 12, 8, and 5 metres came into being in 1907. In order that vested interests should not be unduly disturbed, the Y.R.A. ordained that yachts built under the 1901 rule should be eligible to compete in equivalent classes of the International Yacht Racing Union under special conditions until the end of 1909.

So far as the larger yachts were concerned, the new rule, with its attendant scantling restrictions, has hitherto given every satisfaction, for the vessels built to it have proved fast and handy, whilst their internal accommodation compares favourably with that of cruising craft of like tonnage. In the case of the small boat classes, however, the scantling tables as originally framed were found to be unduly heavy, and ere the season was over a strong protest against the harshness of the construction rules was made by the small yacht sailors of the Solent and East Coast. The thick planking of the topsides and decks seriously affected the stability of such craft, and this defect was aggravated by the freeboard factor of the formula which encouraged a high-sided boat. As the result of representations made by the clubs to the Y.R.A., the classification societies consented to modify the tables for yachts of the smaller classes, and the scantlings were subsequently reduced by about 20 per cent. all round.

The introduction of the International Rules marked the dawn of a new era in the sport of yacht racing. Under their provisions a yacht can race in any country affiliated to the Union upon terms of perfect equality, and her sphere of action is thus enormously increased. In place of a leaky racing-machine, the yachtsman now has a strong and faithfully constructed craft to which a long life of general utility is assured. When outclassed for racing in her home waters there is a market of European extent available for her disposal, whilst by a mere reduction of sail area she is converted into a speedy and efficient cruiser.

The initial cost of construction is perhaps slightly greater than of yore, but the owner receives far better value for his money. Take, for example, the modern first-class cutter-a vessel of 23 metres rating. She is of composite build, the strongly constructed steel frame being planked with 24-inch mahogany of hard texture, and she is classed for a term of sixteen years.

But it is in the matter of habitability that the present-day racing yacht shows such a marked improvement upon her predecessors. The internal accommodation of a 23-metre cutter comprises a large saloon, a commodious after-cabin, with bathroom adjoining, a comfortable owner's cabin, two spare state rooms, a second bathroom, and a deckhouse companion which will accommodate six or eight persons in bad weather. A large and airy fo'castle provides sleeping accommodation for the crew of twenty-two hands, and the galley and pantry arrangements are all that could be desired. There is a comfortable cabin for the captain adjoining the fo'castle, and a large sail room in the vessel's counter. “ Although smaller than the first-class cutters of the days of "Britannia," "Valkyrie," and Satanita," the modern yacht is large enough to afford the very best of sport, and, under a trysail, is capable of keeping the seas in almost any weather. Her approximate dimensions are:

Length for rating purposes, 81 ft.; beam, 21 ft. 6 ins.; draught to ft. 9 ins., and sail area about 9,500 sq. ft. In such a yacht the owner and his guests can live in comfort throughout the season, cruising round the coast and racing at all the principal regattas. He consequently has far better value for his money than was the case in the old days when racing yachts were mere shells with hardly sufficient accommodation for the crew.

That the international rating formula is perfect in every detail would be too much to say, but the yachts hitherto produced under it, at any rate in the larger classes, certainly approach nearer to the ideal than those built under any other rule within the memory of the present generation of yachtsmen.

It is perhaps a matter for regret that when the construction rules were drafted the Classification Societies did not take steps to check the use of unduly light masts in racing yachts. In prohibiting the employment of costly and unreliable hollow masts in the large yacht classes, they certainly took a step in the right direction; but in leaving the diameter of the solid spars used in their place to the discretion of the designer, a loophole was afforded for weight-saving aloft which has been carried to excess. The season of 1910 proved one of the most disastrous in the annals of the sport, and the many casualties that occurred must, almost without exception, be directly attributed to the employment of masts of insufficient strength. The big cutter "Brynhild" was dismasted off Felixstowe, and the heel of the broken spar piercing her hull caused her to sink within a few minutes, whilst a month later "White Heather" was dismasted on the Clyde, her sails and gear being completely ruined.

Amongst the smaller yachts, comparatively few went through the summer without the loss of at least one mast, and the season was brought to a premature conclusion by the dismasting of the 12-metre cutter "Cintra," when two of her crew were knocked overboard and drowned.

All matters relating to rules for determining rating, to measurement and the granting of certificates, to the rules of the road to be observed during races, and to many other details connected with racing, are under the control of a body styled the Yacht Racing Association.

This association was formed in the year 1875 by Count-now Prince-Batthyany, the Marquis of Exeter, Sir George Leach, and Mr. Dixon Kemp, and originally consisted of the owners of racing yachts of and above IO tons measurement, "such other gentlemen as the committee might elect." The functions of the Association have been the framing and forming the various rules of measurement of tonnage and rating, the arrangement of the sailing rules of yacht racing, and the settlement of such protests and questions of dispute as may be referred to them by sailing committees by desire of the parties interested or otherwise. The rules of the Association, however, provide that the decisions of sailing committees shall be final unless they think fit to bring the matters under discussion before the Council for their decision. At the present time the Yacht Racing Association, under the Patronage of His Majesty the King, and Presidency of Sir George Leach, consists of a Council of 24, and about 100 members, almost entirely composed of yacht owners and members of the leading yacht clubs, and 52 club delegates.

The Association decrees that a certificate of measurement of rating shall be held by every yacht starting in a match, which certificate states in detail the various measurements of hull and sail area necessary to determine the rating of the vessel. These measurements are taken by the Association's own official measurers at all the principal yachting centres. Mixed between vessels of different rigs are discouraged by the Yacht Racing Association, which aims at dividing yachts as far as is possible into separate and distinct classes according to the rating. races Provision is made in the rules that racing craft shall use no shifting ballast of any kind; that every yacht exceeding 12 metres rating shall carry, when racing, a boat ranging in size from of the yacht, with oars lashed and ready for IO ft. to I2 ft. in length, according to the rating immediate use; and that all yachts exceeding ordinary fittings of a yacht, including one or 7 metres rating shall be fitted below deck with the more transverse bulkheads of wood. The greater part of the work of the Yacht Racing Association Council consists in hearing and adjudicating upon protests referred to them by sailing committees, which is nearly always done in the not improbable case that the decision of the committee is considered unsatisfactory by one of the parties interested. mo The position that the Yacht Racing Association holds in yacht racing is to some extent similar to that which the Jockey Club occupies in respect to the Turf, but most unfortunately its powers are not so complete. Its relation, for instance. to the increasing number of local classes, and one design" classes both in the Solent, Clyde, Irish waters, and round the coast generally, is at present somewhat ambiguous, and it exercises but little effective control over the eccentricities of ignorant or foolhardy sea jockeys.

It may be interesting to consider the creation of a racing yacht. A person of sporting instincts and seafaring proclivities determines to build a racing yacht of a certain class or rating, and consults a designer.

The first question to be decided is what is to be the strong point of the proposed ship: is she to be a fine weather boat, a hard weather boat, or an all-round boat? If designed to sail exceedingly fast in light breezes, she certainly will not excel in strong breezes; if sailing fast in hard winds is to be her principal merit, she cannot be expected to obtain phenomenal speed in light airs; if intended to be equally good in all weathers, super-excellence will be sacrificed to general utility. Unfortunately neither intuition nor meteorological science are very reliable guides "VALKYRIE. in forecasting weather, and a man building a light weather boat may find himself very much out of it during a windy summer, while a stormy petrel may bitterly bewail the prevalence of light winds during an unusually fine season. But, as a matter of fact, the difficulty of choice is generally solved by a desire to beat some particular yacht. Some crack among the 23- or 15-metre boats may have kept pride of place for two or three seasons, and the ambition of the prospective owner will be to beat that particular vessel, and ambition will therefore dictate instructions to the designer.

Yacht designing is a most maddening, complicated, and beautiful art. A successful racing vessel consists of a bundle of compromises, most perfectly balanced, and adjusted into a symmetrical and harmonious whole; and without going deeply into the subject, some account of the conflicting principles which the perplexed designer has to reconcile is necessary in order to understand the nature of his art.

Those principles in hydrostatics which show that a body floating in water displaces a volume of water exactly equal in weight to the weight of the body, and adapts itself as regards depth and line of flotation according to its peculiarities of form and the situation of its centre of gravity, have become so generally understood as to render any unnecessary. detailed reference to them They form, however, the foundation upon which a designer has to work. With probably a wealth of experience, and numerous actual examples in the shape of previous successful productions to fall back upon, it is not necessary that a designer should begin to scheme out the elements of any new creation purely on the lines of abstract science. Nevertheless, in yacht designing, more than in any other branch of marine architecture, careful regard to scientific principles, tempered by practical experience, is essential. That science alone cannot be relied upon is proved by the tentative methods adopted, and the slow degrees whereby approximate perfection is arrived at, under any new rating rule. A wise designer, therefore, will especially if restricted by a rating formula of which he has not had much experience-proceed on scientific principles, but also on the system of "trial and error." Whatever plan or combination of plans be adopted, the essential properties and characteristics of the proposed vessel have to be schemed out mentally, and tentatively figured down, before the graphic process of giving actual form to the vessel is proceeded with.

A short, but for the purpose sufficiently accurate, statement of some of the principles affecting a floating body will help to the better understanding of the nature of the problems which the yacht designer has to solve.

A vessel, floating upright and at rest in still water, will fulfil two conditions: first, as already stated, she will displace a weight of water equal to her own weight: and secondly, her centre of gravity will lie in one and the same vertical line with the centre of gravity of the volume of water displaced, or, as it is called, with the centre of buoyancy. The whole weight of the vessel may be supposed to be concentrated at her centre of gravity, and to act vertically downwards, and the resultant pressure of the surrounding water may in the same way be said to act vertically upwards through the centre of buoyancy.

When a ship is inclined from the upright position through any cause extraneous to herself, for instance, through the pressure of wind on the sails, the downward and upward forces of weight and buoyancy respectively act through their respective centres in two separate but parallel vertical lines, and form what is technically known as a "couple." The horizontal distance between the vertical lines varies with the inclination, and is called the "arm" of the couple. This arm measures the leverage with which the weight and the buoyancy of the vessel tend either to force her back into an upright position or to incline her to a still greater angle. The former effect is the result of what is known as a "righting" couple; the latter, as an "upsetting" couple.

From a consideration of these facts it will be seen that the centre of gravity in every properly designed vessel must be in such a position as to be below the point of intersection of a line passing through the centre of buoyancy, as shifted out when the ship is inclined, and the vertical plane of the ship, which point of intersection is called the meta-centre. The combined effect of both forces in this case is to rotate the vessel upwards towards the upright position; in other words, they form a righting couple.

In the opposite case, where the centre of gravity-either initially through top-heaviness, or as the result of a shifting of weight on board - falls to the other side of the vertical line, acting upwards through the centre of buoyancy when the vessel is inclined, the effect is to rotate the vessel in the direction of her inclination, and eventually to capsize her; that is to say, the forces form an upsetting couple.

When neither of these results positively follows, but the inclination from the upright is simply maintained, as in the case of a yacht under wind propulsion, the force of gravity, plus that due to wind pressure, is balanced by the force of buoyancy, and the stability of the vessel may be considered satisfactory. a The curve of stability of a vessel consists of curve traced along the extremities of the lengths of the righting and upsetting arms at stated angles of inclination, set off from a base line, the former being set off above and the latter below the line. Or sometimes, and perhaps more conveniently, the curve set off, instead of being a curve of " arms," represents a curve of "moments"-that is to say, of the lengths of the arms multiplied into the displacement. a The centre of buoyancy is determined with almost absolute accuracy from the displacement calculation, into which, in an article of this nature, it is unnecessary to go.

The centre of gravity can be found by calculation, after the size, scantling, and position of the various materials forming the vessels have been ascertained and fixed, by first finding the position of the centre of gravity of each of the component parts, and from this deducting the common centre of gravity of the whole vessel, including spars, rig, and equipment. As, however, this process cannot be entered upon, except very roughly, until the form, scantling, and position of all the various the corresponding heights may be as much as 8 or IO feet.

For preliminary purposes, a fair approximation may be made of the volume of displacement appertaining to a suitable form of hull of given dimensions by assessing it as a percentage of the capacity given by the products of the three principal dimensions. This percentage is known as the "block co-efficient." Or an approximation may be arrived at by assessing the relation between the volume of displacement and that of a prism, having for its base the immersed midship cross-section of the vessel, and for its length her proposed length on the load-water-line. This percentage is called the "prismatic co-efficient."

By either of these means a fairly accurate estimate can be obtained of the displacement which will be the product of any proposed dimensions, and conversely from this result a more definite determination can be made as to what the precise dimensions should be.

The conventional centre of effort, that is, the centre of the effect of the propulsive power of the wind upon the sails, must also be considered.

This is arrived at by simple triangulation applied first to each of the sails, and from those various W GO B FIG. 1 W GOZ B M FIG. 2 L W 2G MΦ B FIG 3 L.

FIG. I represents a vessel upright, with her centre of gravity in a normal position.

G is the centre of gravity, B the centre of buoyancy. WL the water-line. VV the vertical line passing through the centre of gravity.

FIG. 2 represents a vessel inclined, the centre of gravity being properly placed at G. B is the centre of buoyancy shifted out by the inclination of the vessel. Mis the meta-centre. GZ is the couple, and it is a righting couple, as the force of buoyancy acting perpendicularly upwards through Z rotates the vessel towards an upright position. parts have been fixed, and as the calculation is in any case laborious and liable to error, it is usual to arrive at the position of the centre of gravity, approximately, from data derived from calculations of similar vessels previously built, or from results obtained, purely experimentally, by inclining existing vessels to various angles.

Another term essentially concerned with stability is the "meta-centre," mentioned above.

The meta-centre is the point where the new line of upward support, when the vessel is inclined at a small angle, intersects the original line when she was upright. The point can be determined from the displacement calculations. "Meta-centric" height, that is, the distance or interval between the meta-centre and the centre of gravity, is an important measure of the stability of vessels, and in all cases where the type is not much out of the common, meta-centric stability is the only measure which it is necessary to take into account. The value that meta-centric height should possess varies with the type of vessel, but only to a small extent, unless the types vary very largely. In six yachts, whose stability was carefully investigated by the late Mr. Dixon-Kemp, the meta-centric height ranged from 3 feet in "Kriemhilda" and 3 feet 6 inches in "Miranda" to 4 feet in the "Rose of Devon." In the case, however, of very broad shallow-bodied yachts,