IV. BOATS OF 10FT., 12FT., 14ft., 15FT., AND 20FT., DITTO... 261 275 VI. SAIL PLAN OF "LE LISON " FRENCH CENTRE-BOARD YACHT 276 VII. SAIL PLAN CHINESE LUG SAIL 281 XXI. ITCHEN BOAT "CENTIPEDE," 22FT. 8IN. AND 21FT. 343 XXVI. DESIGN FOR YACHTS OF 10 TONS AND 5 TONS 361 362 TO FACE PAGE XXVIII. "FREDA," 5 TONS YACHT 362 XXIX. "WITCH," LOUGH ERNE YACHT. 368 XXX. "HEATHEN CHINEE," IRISH MODEL YACHT CLUB BOAT... 371 XLII. "NAUTILUS" CRUISING CANOE SPAR AND RIGGING PLAN 447 YACHT AND BOAT SAILING. INTRODUCTION. THE ART OF YACHT AND BOAT SAILING cannot be acquired by the mere study of books which treat of the subject, but precise instruction will always be of value to those who have had no experience in youth of the sport, or who have no opportunities of taking advantage of practical coaching. Yacht sailing, like many other arts, is governed by certain scientific principles, easily determinable in theory, although hidden in practice. Experience has taught every sailing master that, if a vessel carries too much weather helm, an addition to head-sail or reduction of after-sail will ameliorate it; and he equally knows that, if a vessel is deficient in stiffness, the application of a lead keel will make her stiffer; but if he were told to shorten the arm of the couple upon which acted the force that was turning the vessel's head towards the wind, or to lengthen the arm of the couple upon which the statical stability of the vessel depended, he probably would not know what was meant. argued that, if a man knows what to do to correct certain objectionable conditions, it does not matter whether he can account scientifically for the cause and effect, or for the evil and the cure. But it is obvious that a man, although expert in the practice of his art so long as everything worked smoothly, would be liable to meet with a check if any adverse condition refused to yield to remedies within his experience; whereas, if he had a knowledge of the underlying principles of his art, the remedy would be suggested because the cause of the evil would be known. However, the object in view is not to instruct sailing masters in the scientific principles which govern their art, but to give such instruction and knowledge of the practice of that art as may be of service to the purely uninitiated. This knowledge can be most readily imparted if a clear understanding B It may be is first arrived at of the principles and properties which, according to scientific research, govern the performances of sailing vessels. With this purpose in view, will be given, in as succinct form as may be compatible with clearness, a statement of those principles and properties before the general subject of the management of a vessel when under sail is entered upon. The exact application of principles or the determination of properties referred to would be beyond the scope of this work, and can be acquired from some modern work on naval architecture, such as "Yacht Designing." CHAPTER I. DISPLACEMENT AND BUOYANCY-STABILITY. DISPLACEMENT AND BUOYANCY. THE displacement of a vessel is the quantity or bulk of water (generally represented by a measure of weight) which a vessel displaces or pushes away when she is put into the water. This quantity of water is always equal to the whole weight of the vessel and everything that she contains; that is to say, the vessel will sink into the water until she has displaced a quantity of the fluid equal to her own weight and the weight of everything that she contains. If the weight of water displaced is also exactly equal in bulk to the bulk of the vessel, then the latter will sink in the fluid until her entire bulk is immersed; or, in other words, if the body immersed be a solid of the specific gravity of the water, then will the solid sink into the fluid until it is entirely immersed. For example, a cubic foot of African oak weighs 621b., a cubic foot of fresh water weighs 624lb., and consequently, if a cubic foot of African oak were placed in fresh water, it would nearly sink to the level of the surface; but a cubic foot of sea water weighs 64lb., and consequently, if a cubic foot of African oak were placed into sea water, it would sink until 62lb. of the fluid were displaced (which would be less than a cubic foot), and would sink no deeper, so practically 2lb. of the oak cube would remain above the surface. This well illustrates the meaning of the term "a vessel's displacement." A vessel weighs, we will say, with all her ballast, spars, sails, gear, stores, crew, and everything belonging to her on board, one ton; then, if she is put into the water, she will displace exactly one ton of the fluid. Now a ton of sea water in bulk contains 35 cubic feet; consequently, if the bulk of the vessel only equalled 35 cubic feet, she would sink into the water until entirely immersed. But a vessel that weighed one ton would contain in bulk a great deal more than 35 cubic feet, measuring her actual body on the outside from keel to deck as if she were a solid; that is, the whole body or bulk of the vessel so measured would probably equal 50 |