Keel (anatomy)

“ The separation of species is difficult and, in part, doubtful. Keel excentric.
7. Bilobatæ.—Like the group Dubiæ, but with more central keel and so forming a transition to the group Pseudo-Amphiprora; valves without longitudinal folds.
8. Pseudo-Amphiprora.—Valve with quite central, sharp keel, arcuate, without longitudinal fold; keel puncta always evident; frustule narrowed in the middle with more or less marked central nodule.
Includes two species not found in this locality.
9. Perrya.—Valve arched with very sharp central keel; not narrowed in the middle ”

“ Sliding keels must weaken a vessel in the most essential part – her keel; for it may be called the back-bone of a vessel; and unless animals had two instead of one, it is most likely that one keel is more compact, and stronger than two. Sliding keels take up part of the stowage of a ship or vessel ”

“ That keel, which with the sharpness of a scythe has so often mowed its course through the reluctant wave, is now buried—buried deep in the sand, which the angry surge accumulates each minute, as if determined that it never will be subject to its weight again. ”

“ The keel of a ship has been likened to the backbone of a man, running, as it does, from stem to rudder. It consists of several timbers scarfed or pieced together, and under it is the shoe, a kind of second keel, but differing from the keel proper in that it is only loosely joined to it, whereas the keel is bolted to the ship's bottom through and through. The reason for this is that in case of grazing a rock a vessel having a shoe will, in most cases, part with the shoe, thus saving the keel, and escaping without serious injury. ”

“ Everything in naval architecture springs from and is related to the keel. 'Laying the keel' means beginning the ship in the only possible way, and 'two keels to one' is an expression which every one understands as meaning a naval preponderance in that proportion. The keel is to the ribs of a ship exactly what the backbone is to the ribs of a man, and any craft built up from a keel, no matter how small and simple it may be, belongs to the third and apparently final type of craft, which is as far ahead of the canoe type as that is ahead of the dug-out, raft, and log. ”

“ It is the beam which runs along the bottom of a boat or ship from one end to the other. In large ships the keel consists of several pieces joined together. Its uses are, to cause the ship to preserve a direct course in its passage through the water; to check the leeway which every vessel has a tendency to make; and to moderate the rolling motion. The keel is also the ground-work, or foundation, on which the whole superstructure is reared, and is, therefore, immensely strong and solid. The best wood for keels is teak, as it is not liable to split. ”

“ Next, saw into both ends of your keel piece, insert the stem and stem pieces; then plane the keel piece so that it will come to a point both forward and aft. Fasten these uprights to the keel with copper nails or rivets. They are better than any other kind because they do not rust. ”

“ Each keel carries about twenty tons of coal, the larger masses being piled up in the vessel, but smaller coal is carried in tubs, each keel having about eight tubs. The keels are antique-looking craft, such as were probably used in the earliest days of our history. They are propelled by large oars. The keel man, commencing at the bow, presses the oar before him, until he reaches the after part of the boat; he then hurries back to the bow, and again puts down his oar. The keel men are a fine hardy race. ”

“ General View of the Frames of the City of New York—June 25, 1887.
The keel is laid down on blocks, four or five feet apart, which form a slope toward the water, so that the hull may glide down easily when the time for launching comes. It is not a keel at all, in the sense in which the word was formerly used: a modern ship has a smooth bottom, without any projecting ridge or break to the curve of her sides; it is simply the central series of plates, from which an inner keel is built up like an enormous backbone, and to this the ribs are attached. ”

“ The first piece of timber laid upon the blocks is generally the keel; I say generally, because, of late, a different method has been adopted in some of the royal dock-yards, by beginning with the floor-timbers; the artists having found that the keel is often apt to rot during the long period of building a large ship of war. The pieces of the keel, as exhibited in plate I. are scarfed together, and bolted, forming one entire piece, A A. which constitutes the length of the vessel below. At one extremity of the keel is erected the stem. ”

“ The first thing that strikes the observer of its skeleton is the extraordinary structure of the sternal apparatus, which is wholly unlike that of any other bird known. The keel is only developed on the posterior part of the sternum—the fore part being, as it were, cut away, while the short furcula at its symphysis meets the manubrium, with which it is firmly consolidated by means of a prolonged and straight hypocleidium, and anteriorly ossifies with the coracoids. ”

“ When all the parts are prepared, the keel is laid upon blocks, and the planks being supported by stanchions, are sewed or clamped together with strong thongs of plaiting, which are passed several times through holes that are bored with a gouge or auger of bone, that has been described already ”

“ The modern usage in Dutch and German has approximated to the English. The word kiel is represented in old English by céol, a word applied to the long war galleys of the Vikings, in which sense “keel” or “keele” is still used by archaeologists. On the Tyne “keel” is the name given to a flat-bottomed vessel used to carry coals to the colliers. There is another word “keel,” meaning to cool, familiar in Shakespeare (Love’s Labour Lost, v. ii. 930) , “while greasy Joan doth keel the pot,” i.e. prevents a pot from boiling over by pouring in cold water, &c., stirring or skimming. ”

“ If you only want to punt about in smooth water and in shallows, you can dispense with any exterior keel, and in any case you can easily screw on a false keel of whatever depth you consider necessary afterwards. ”

“ When you have all your pieces nicely planed, be careful to follow your dimensions, lengths, etc., and don't saw off an inch too much. Now for the keel and bowsprit. Measure off from the right-hand end of the keel four feet six inches on the under edge; then cut to the right hand with draw-knife down to two inches; finish with plane. ”

“ I prefer to be original, but at the same time in the interests of my crew I do not hesitate to adopt well-established devices. To each of the three sections of this vessel is fixed a detachable iron keel. The bolts are secured on the keelson by a single yet effective looking device. One thrust of a lever and a section of this keel is dropped. Should a compartment be half full of water there is sufficient buoyancy gained by the release of this dead-weight to lift the vessel to the surface. ”

“ NITZSCHIA LINEARIS (AG.) WM. SM.
Valve linear, slightly inflexed in the middle; keel excentric; keel puncta, 8-9 in 10 μ, the two median distant; striæ about 30 in 10 μ. Frustules in zone view narrowed toward the ends, truncate. L. 75 μ.
Very common in fresh water.
Pl. 32, Fig. 18. Fig. 20, Pl. 40, a transverse section of frustule.
Lanceolatæ
NITZSCHIA PALEA (KUETZ.) WM. SM.
Valve linear-lanceolate, slightly rostrate at the apices; keel puncta, 10 in 10 μ, the median not distant; striæ, 33-36 in 10 μ; zone view linear, with rounded ends. L. 25-65 μ. ”

“ You know you were interested in my little keel scholars, because their vessels were so fine, and because they themselves were once simple bodies, almost guiltless of reading and writing. [395] And it seems as if even the mud gives testimony to your words. So if you don’t mind the bother of one of my tiresome letters, I’ll tell you all I know about them.
“The Humber keels are, in nearly all cases, the property of the men who go in them. They are house and home to the keel family, who never live on shore like other sailors. It is very easy work navigating the rivers. ”

“ In such birds the keel appears as a very slightly raised ridge that forms a distinct line on the palate. The bill at this time has reached about three-fourths of the length attained when the bird is adult, so that the beginning of this ridge appears to be located far forward, though it occupies the same position in relation to the external nasal opening that the fully developed keel does in the adult. In the dried skins the ridge is somewhat indistinct, but it is possible that it may be more readily apparent in living or recently killed specimens. ”

“ The mucous membrane lining the tympanum is continuous through the Eustachian tube with that of the naso-pharynx, and is reflected on to the ossicles, muscles and chorda tympani nerve. It is ciliated except where it covers the membrana tympani, ossicles and promontory; here it is stratified.
The internal ear or labyrinth consists of a bony and a membranous part, the latter of which is contained in the former. The bony labyrinth is composed of the vestibule, the semicircular canals and the cochlea. ”

“ The middle ear or tympanum is an irregular cavity in the petrous portion of the temporal bone. Its outer wall is formed by the membrana tympani or drum, an oval translucent membrane placed obliquely at the bottom of the external auditory canal. The middle ear communicates with the inner ear through the fenestra ovalis or oval window and contains the ossicles, the malleus or hammer, the incus or anvil, and the stapes or stirrup, which are arranged in a movable chain from the drum to the oval window. ”

“ The keel, or carina sterni, is formed as a direct cartilaginous outgrowth of the body of the sternum, ossifying from a special centre. This keel is much reduced in the New Zealand parrot, Stringops, less in various flightless rails, in the dodo and solitaire. It is absent in the Ratitae, which from this feature have received their name, but considerable traces of a cartilaginous keel occur in the embryo of the ostrich, showing undeniably that the absence of a keel in the recent bird is not a primitive, fundamental feature. ”

“ The cavity of the mouth must be large enough to allow of the largest possible wave of sound, since upon the size of that, as we know, the strength of the tone depends. When the pupil, after some practice, has learned to give the right direction to the stream of sound, he must be required gradually to form the other vowels like the soo in the front part of the mouth, passing from this syllable immediately to the other vowels, as, for example, soo-a, soo-o, soo-e, soo-o-e-ah, &c. Only care must be taken that the course of the air preserves its right direction. ”

“ This cavity is hollowed out in dense bone, and consists of three parts; the vestibule (a) , or ante-chamber, which is connected with the other two; the cochlea (b) , or snail's shell; and the three semicircular canals (c) . The manner in which the nerve of hearing is distributed is remarkable, and is peculiar to this nerve. In the vestibule and the canals its fibres are spread out over the inner surface, not of the bony cavity but of a membranous bag, which conforms to and partially fills that cavity; and which floats in it, being both filled and surrounded with a clear, limpid fluid. ”

“ Prior to the discovery of the laryngoscope, the great obstacle to the diagnosis and comprehension of disease of the larynx lay in the fact that this organ was so placed as to be at an almost direct angle to the line of vision. If we look into the mouth of another person, we see the back of the mouth; but if we wish to see the larynx, or organ of tone and voice, we are unable to do it, even though its position is just back of and below the root of the tongue. And, even though we press down the tongue, we derive no aid. ”

“ Every one is aware of the reinforcement of sound by the resonance of cavities. When singing or speaking near the aperture of a wide-mouthed vessel, the intensity of some one note in unison with the air in the cavity is often augmented to a great degree. Any vessel will resound if a body vibrating the natural note of the cavity be placed opposite to its orifice, and be large enough to cover it, or at least to set a large portion of the adjacent air in motion. ”

“ In addition to the singular connection of the ear with the exterior by the roundabout way of the air-bladder, there are membranous spaces in the walls of the skull by which vibrations can more directly reach the herring's ear. And there is no doubt that the fish is very sensitive to such vibrations. In a dark night, when the water is phosphorescent or, as the fishermen say, there is plenty of "merefire," it is a curious spectacle to watch the effect of sharply tapping the side of the boat as it passes over a shoal. ”

“ Experiment 157. To vibrate the tympanic membrane and the little ear-bones. Shut the mouth, and pinch the nose tightly. Try to force air through the nose. The air dilates the Eustachian tube, and is forced into the ear-drum. The distinct crackle, or clicking sound, is due to the movement of the ear-bones and the tympanic membrane.
The cochlea, or snail’s shell, is another chamber hollowed out in the solid bone. It is coiled on itself somewhat like a snail’s shell. There is a central pillar, around which winds a long spiral canal. One passage from the cochlea opens directly into the vestibule ”