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24-446: Jib is a triangular sail at the front of a sailing boat. Jib or JIB may also refer to: Jib Boats may be sailed using a jib alone, but more commonly jibs make a minor direct contribution to propulsion compared to a main sail . Generally, a jib's most crucial function is as an airfoil , increasing performance and overall stability by reducing turbulence on the main sail's leeward side. On boats with only one jib, it

48-455: A nasal cavity inside the head, and an external nose on the face. The external nose houses the nostrils , or nares, a pair of tubes providing airflow through the nose for respiration . Where the nostrils pass through the nasal cavity they widen, are known as nasal fossae, and contain turbinates and olfactory mucosa . The nasal cavity also connects to the paranasal sinuses (dead-end air cavities for pressure buffering and humidification). From

72-470: A vomeronasal organ , lined by olfactory epithelium, but, unlike those of amniotes , this is generally a simple sac that, except in salamanders , has little connection with the rest of the nasal system. In reptiles , the nasal chamber is generally larger, with the choanae located much further back in the roof of the mouth. In crocodilians , the chamber is exceptionally long, helping the animal to breathe while partially submerged. The reptilian nasal chamber

96-499: A boat with two staysails the inner sail is called the staysail , and the outer (foremost) is called the jib. This combination of two staysails is called a cutter rig (or in North America a yankee pair ) and a boat with one mast rigged with two staysails and a mainsail is called a cutter . On cruising yachts, and nearly all racing sailboats, the jib needs to be worked when tacking. On these yachts, there are two sheets attached to

120-456: A kind of filter against airborne illness. In addition to acting as a filter, mucus produced within the nose supplements the body's effort to maintain temperature, as well as contributes moisture to integral components of the respiratory system. Capillary structures of the nose warm and humidify air entering the body; later, this role in retaining moisture enables conditions for alveoli to properly exchange O 2 for CO 2 (i.e., respiration) within

144-418: A long, muscular, manipulative organ called the trunk . The vomeronasal organ of mammals is generally similar to that of reptiles. In most species, it is located in the floor of the nasal cavity, and opens into the mouth via two nasopalatine ducts running through the palate, but it opens directly into the nose in many rodents . It is, however, lost in bats, and in many primates, including humans. Fish have

168-400: A relatively good sense of smell. Unlike that of tetrapods , the nose has no connection with the mouth, nor any role in respiration. Instead, it generally consists of a pair of small pouches located behind the nostrils at the front or sides of the head. In many cases, each of the nostrils is divided into two by a fold of skin, allowing water to flow into the nose through one side and out through

192-416: A relatively poor sense of smell. The nasal cavity of mammals has been enlarged, in part, by the development of a palate cutting off the entire upper surface of the original oral cavity , which consequently becomes part of the nose, leaving the palate as the new roof of the mouth. The enlarged nasal cavity contains complex turbinates forming coiled scroll-like shapes that help to warm the air before it reaches

216-476: Is called the jib , and the innermost is called the staysail . Actually, all three sails are both jibs and staysails in the generic sense. Original usage in 18th and 19th century square-rigged ships distinguished between the fore staysail, set on the forestay running from the foremast head to the ship's peak, the foremost part of the hull, and the jibs set on stays running to the bowsprit. Jibs, but not staysails, could also be "set flying," i.e. not attached to

240-431: Is common for the clew of the jib to be abaft the mast, meaning the jib and mainsail overlap. An overlapping jib is called a genoa jib or simply a genoa (see illustration). These are efficiently used when reaching more broadly than a close reach . Alternatively, a boat may carry smaller jibs, to compensate aerodynamics when the main sail is reefed ; these more rugged sails are called storm jibs or spitfires . On

264-408: Is divided into three parts: an anterior vestibule , the main olfactory chamber, and a posterior nasopharynx . The olfactory chamber is lined by olfactory epithelium on its upper surface and possesses a number of turbinates to increase the sensory area. The vomeronasal organ is well-developed in lizards and snakes, in which it no longer connects with the nasal cavity, opening directly into the roof of

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288-514: The Naval Chronicle (1805)—"we perceived by the cut of their sails, then set, that they were French Ships of War"—is often cited as an early inspiration for the idiom. Sir Walter Scott used the expression to denote approval in the 1824 novel St. Ronan's Well : "If she disliked what the sailor calls the cut of their jib " . John Russell Bartlett later defined the idiom in his 1848 Dictionary of Americanisms as "The form of his profile,

312-415: The clew of the jib. As the yacht comes head to wind during a tack, the active sheet is released, and the other sheet (the lazy sheet ) on the other side of the boat is pulled in. This sheet becomes the new active sheet until the next tack. Schooners typically have up to three jibs. The foremost one sets on the topmast forestay and is generally called the jib topsail , a second on the main forestay

336-535: The anterior part of the upper jaw of the reptilian-like ancestors ( synapsids ). Acting as the first interface between the external environment and an animal's delicate internal lungs, a nose conditions incoming air, both as a function of thermal regulation and filtration during respiration, as well as enabling the sensory perception of smell. Hair inside nostrils filter incoming air, as a first line of defense against dust particles, smoke, and other potential obstructions that would otherwise inhibit respiration, and as

360-400: The cast of his countenance". This usage alludes to a frequent variation of meaning which describes approval, specifically, of the shape of one's nose , which roughly approximates the frontal position and triangular shape of the jib sail on a boat. Nose This is an accepted version of this page A nose is a sensory organ and respiratory structure in vertebrates . It consists of

384-416: The lungs. During exhalation, the capillaries then aid recovery of some moisture, mostly as a function of thermal regulation, again. The wet nose of dogs is useful for the perception of direction. The sensitive cold receptors in the skin detect the place where the nose is cooled the most and this is the direction a particular smell that the animal just picked up comes from. In amphibians and lungfish ,

408-431: The lungs. The cavity also extends into neighbouring skull bones, forming additional air cavities known as paranasal sinuses . In cetaceans , the nose has been reduced to one or two blowholes , which are the nostrils that have migrated to the top of the head. This adaptation gave cetaceans a more streamlined body shape and the ability to breathe while mostly submerged. Conversely, the elephant 's nose has elaborated into

432-473: The mouth. It is smaller in turtles, in which it retains its original nasal connection, and is absent in adult crocodilians. Birds have a similar nose to reptiles, with the nostrils located at the upper rear part of the beak . Since they generally have a poor sense of smell, the olfactory chamber is small, although it does contain three turbinates, which sometimes have a complex structure similar to that of mammals . In many birds, including doves and fowls ,

456-471: The nasal cavity, the nostrils continue into the pharynx , a switch track valve connecting the respiratory and digestive systems . In humans, the nose is located centrally on the face and serves as an alternative respiratory passage especially during suckling for infants . The protruding nose that is completely separate from the mouth part is a characteristic found only in therian mammals . It has been theorized that this unique mammalian nose evolved from

480-470: The nostrils are covered by a horny protective shield. The vomeronasal organ of birds is either under-developed or altogether absent, depending on the species. The nasal cavities in mammals are both fused into one. Among most species, they are exceptionally large, typically occupying up to half the length of the skull. In some groups, however, including primates , bats , and cetaceans , the nose has been secondarily reduced, and these animals consequently have

504-446: The nostrils open into small sacs that, in turn, open into the forward roof of the mouth through the choanae . These sacs contain a small amount of olfactory epithelium, which, in the case of caecilians , also lines a number of neighbouring tentacles. Despite the general similarity in structure to those of amphibians, the nostrils of lungfish are not used in respiration, since these animals breathe through their mouths. Amphibians also have

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528-403: The other. The pouches are lined by olfactory epithelium, and commonly include a series of internal folds to increase the surface area, often forming an elaborate "olfactory rosette". In some teleosts , the pouches branch off into additional sinus-like cavities, while in coelacanths , they form a series of tubes. In the earliest vertebrates, there was only one nostril and olfactory pouch, and

552-488: The standing rigging. Sails set beyond the peak were typically called jibs, set on stays running from the fore topmast to the bowsprit , or the fore topgallant mast to the jibboom or even the fore royal mast to the flying jibboom. A large square-rigged ship typically has four jibs, but could have as many as six. From forward to aft, these sails are called: The first two were rarely used except by clipper ships in light winds and were usually set flying. A storm jib

576-481: Was a small jib of heavy canvas set to a stay to help to control the ship in bad weather. The jib is referenced in the idiom usually spoken as "I like the cut of your jib", generally seen as signifying approval of one's general appearance or respect for their character. The phrase alludes to the maritime practice of identifying far-away ships by noting the "cut" (general shape and configuration) of their sails to determine their status as friend or foe. One such report from

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