The ovary, of two carpels, is seated on a ring-like disk FIG.
The foot of the Pectinibranchia, unlike the simple muscular disk of the Isopleura and Aspidobranchia, is very often divided into lobes, a fore, middle and hind lobe (pro-, mesoand meta-podium, see figs.
The hieroglyph of some other early sun temples shows a disk on the pyramidion.
In the case of close double stars he estimated the distance in terms of the disk of the components.
a crystal or glass circular disk, more suited to the shape of the sacred wafer; this is mounted in a frame of golden rays, and the whole is supported by a stem and bases.
When it is merely a luminous disk round the head, it is called specifically a nimbus, while the combination of nimbus and aureole is called a glory.
by the disk, for any difference in speed between nut and screw will cause the nut to move along the screw until the diameter of the cone is reached which fulfils the above conditions for equality in speed.
I I the edge of the disk serves as the pointer and the scale gives the percentage of slack, or (N - n)/n.
The armature acts on an inking disk on the principle described above, save only that the disk is supplied with ink from a groove in a second wheel, on which it rolls: the grooved wheel is kept turning with one edge in contact with ink in an ink-well.
Marconi causes the spark balls to move rapidly past each other or causes a studded disk to move between the spark balls.
To the brass bottom of the case is attached 'a thin disk of polished hard carbon C, which is slightly less in diameter than the brass bottom, so that the carbon disk almost entirely covers this brass back, leaving only a slight annular space around its edge.
It is attached to a brass disk E, which is fastened to the centre of the diaphragm F by means of a rivet, and is capable of moving to and fro like a plunger when the diaphragm vibrates.
A, A hydriform person giving rise to medusiform person by budding from th margin of the disk; B, free swimming medusa (Steenstrupia of Forbes) detached from the same, with manubrial genitali.
The true balsam poplar, or tacamahac, P. balsamifera, abundant in most parts of Canada and the northern States, is a tree of rather large growth, often of somewhat fastigiate habit, with round shoots and oblong-ovate sharp-pointed leaves, the base never cordate, the petioles round, and the disk deep glossy green above but somewhat downy below.
The arc is produced by leading a current of about 5000 volts equatorially between the poles of an electromagnet; this produces what is practically a disk of flame, 62 ft.
The disk really consists of a series of successive arcs which increase in size until they burst.
16), extending between the fenestra ovalis and the tympanic membrane or drum, consists of (I) the long and slen der columella, a straight, ossified rod which fits with a disk into the fenestra r; t st ovalis; it is homologous with the stapes (m.st.), although not stirrupshaped; (2) the extra-columellar mass.
Sometimes the glands are found beneath the disk of the elytron, opening by pores on the surface.
In 1908 a remarkable discovery was made by the Italian Mission at Phaestus of a clay disk with imprinted hieroglyphic characters belonging to a non-Cretan system and probably from W.
4, r) in which the viscid disk of the pollen-masses is concealed till released in the manner presently to be mentioned.
The foot of the limpet is a nearly circular disk of muscular tissue; in front, projecting from and raised above it, are the head and neck (figs.
(After Keferstein.) disk or shield.
The earth is conceived of as a round disk, slightly sloping towards the south, surrounded on three sides by the sea, but on the north by a high mountain of turquoises; behind this is the abode of the blest, a sort of inferior paradise, inhabited by the Egyptians who were saved from drowning with Pharaoh in the Red Sea, and whom the Mandaeans look upon as their ancestors, Pharaoh himself having been their first high priest and king.
The gobies (Gobius) are small fishes readily recognized by their ventrals (the fins on the lower surface of the chest) being united into one fin, forming a suctorial disk, by which these fishes are enabled to attach themselves in every possible position to a rock or other firm substances.
To explode the charge an iron weight, known as a go-devil, was dropped into the well, and striking the disk exploded the cap and fired the torpedo.
The god of Atha was a form of Horus (Apollo) as the sun-god; his most characteristic representation is as the disk of the sun with outspread wings, so often seen over the doors of shrines, at the top of stelae, &c. In the temple, where he is often figured as a falconheaded man, he is associated with Hathor of Dendera and the child Harsemteus.
Up to about the middle of the 19th century it was supposed that transits of Venus across the disk of the sun afforded the most trustworthy method of making the determination in question; and when Encke in 1824 published his classic discussion of the transits of 1761 and 1769, it was supposed that we must wait until the transits of 1874 and 1882 had been observed and discussed before any further light would be thrown on the subject.
One was to use a heliometer to measure the distance between the limbs of Venus and the sun during the whole time that the planet was seen projected on the solar disk, and the other was to take photographs of the sun during the period of the transit and subsequently measure the negatives.
The planets in question appeared in the telescope as star-like objects which could be compared with the stars with much greater accuracy than a planetary disk like that of Mars, the apparent form of which was changed by its varying phase, due to the different directions of the sun's illumination.
The large showy flowers are visited by insects for the honey which is secreted by a ring-like disk below the ovary; large Convolvulus sepium, slightly reduced.
An interesting exception to the general rule that full brightness requires the existence of the first zone occurs when the obstacle assumes the form of a small circular disk parallel to the plane of the incident waves.
Thus in the case of the circular disk, equidistant (r) from the source of light and from the screen upon which the shadow is observed, the width of the first exterior zone is given by = X(2r)/4(2x), 2x being the diameter of the disk.
The efficiency of a telescope is of course intimately connected with the size of the disk by which it represents a mathematical point.
The censer used was a hemispherical cup or bowl of bronze, supported by a long handle, fashioned at one end like an open hand, in which the bowl was, as it were, held, while the other end within which the pastils of incense were kept was shaped into the hawk's head crowned with a disk, as the symbol of Re.'
How far apart, think you, dwell the two most distant inhabitants of yonder star, the breadth of whose disk cannot be appreciated by our instruments?
4), in an early form, consisted of a cell of insulating material having at its bottom a flat-headed platinum screw G; on the top of G was a layer of carbon powder C, on the top of that a platinum disk D, and above that again, forming the cover of the cell, a disk of ivory B, held in position by a ring E.
Resting on the centre of the ivory disk was a small piece of rubber tubing, and this was lightly pressed by the diaphragm A, which was held in place by the mouthpiece M.
In the specification of the patent applied for on the list of July 1877 he showed a sketch of an instrument which consisted of a diaphragm, with a small platinum patch in the centre for an electrode, against which a hard point, made of plumbago powder cemented together with india-rubber and vulcanized, was pressed by a long spring, the pressure of the carbon against the platinum disk being adjusted by a straining screw near the base of the spring.
The box is thus entirely closed at the front, while the front carbon disk, which constitutes an electrode, is perfectly free to follow the motions of the diaphragm.
preceded by six per cartilaginous margin of the radial and six interradial disk centripetally in the solid larval tentacles).
outer surface of the jellyCartilaginous margin of the like disk; six of these are disk covered by thread perradial, six interradial, cells.
In some species of Rana and Staurois inhabiting mountainous districts in south-eastern Asia, the larvae are adapted for life in torrents, being provided with a circular adhesive disk on the ventral surface behind the mouth, by means of which they are able to anchor themselves to stones.
is a flat disk, circular or elliptical in outline, had in the ideas time of Homer acquired a special definiteness by the introduction of the idea of the ocean river bounding the whole, an application of imperfectly understood observations.
Cephalic disk enlarged anteriorly, forming an open tube posteriorly; shell external, thick, with p:ominent spire; no operculum.
the shadow of a circular disk and of a screen circularly perforated.
Problems not limited to two dimensions, such for example as the shadow of a circular disk, present great difficulties, and have not hitherto been treated by a rigorous method; but there is no reason to suppose that Fresnel's results would be departed from materially.
Jelly of the disk.
- Portions of Sections through will be brought about if the Disk of Medusae - the upper one of the medusae mature Lizzia, the lower of Aurelia.
1, Jelly of the disk.
Tozer 2 as the father of geography on account of his Periodos, or general treatise on the earth, did not advance beyond the primitive conception of a circular disk.
Moreover, the pollen, instead of consisting of separate cells or grains, consists of cells aggregated into "pollen-masses," the number varying in different genera, but very generally two, four, or eight, and in many of the genera provided at the base with a strap-shaped stalk or "caudicle" ending in a flattish gland or "viscid disk" like a boy's sucker.
The ears are short, and the hair round the eyes forms a disk.
The subsequent revivals of brightness forming the bright rings are necessarily of inferior brilliancy as compared with the central disk.
If the blowing iron is held vertically with the bulb uppermost the bulb becomes flattened and shallow, if the bulb is allowed to hang downwards it becomes elongated and reduced in diameter, and if the end of the bulb is pierced and the iron is held horizontally and sharply trundled, as a mop is trundled, the bulb opens out into a flattened disk.
A full account of the process of blowing crown-glass will be found in all older books and articles on the subject, so that it need only be mentioned here that the glass, instead of being blown into a cylinder, is blown into a flattened sphere, which is caused to burst at the point opposite the pipe and is then, by the rapid spinning of the glass in front of a very hot furnace-opening, caused to expand into a flat disk of large diameter.
This only requires to be annealed and is then ready for cutting up, but the lump of glass by which the original globe was attached to the pipe remains as the bullion in the centre of the disk of glass.
An oblate flattened body, like a disk or plate, has c 2 -c 1 negative, so that the medium steers the body axially; this may be verified by a plate dropped in water, and a leaf or disk or rocket-stick or piece of paper falling in air.
Each has a small calyx in the form of a shallow rim, sometimes five-lobed or toothed; five petals, which cohere by their tips and form a cap or hood, which is pushed off when the stamens are ripe; and five free stamens, placed opposite the petals and springing from a fleshy ring or disk surrounding the ovary; each bears a twocelled anther.
The anomalous position of the stamens in front of the petals is explained by the abortion or non-development of an outer row of stamens, indications of which are sometimes seen on the hypogynous disk encircling the ovary.
This hopper was divided into two parts by vertical division plates, against the bottom edge of which the knives in the disk forced the roots and sliced and pulped them.
Knives are arranged around their circumference in such a way that the hopper feeding them presents an annular opening to the disk, say 7 ft.
To prevent this various implements, such as disk harrows and specially constructed rollers, may be used to consolidate the upper stirred portion of the soil and place it in close capillary relationship with the lower unmoved layer.
The coulter (either knife or disk) and sometimes a skim-coulter (or jointer) are attached adjustably to the beam, so as to act in the front of the share.
The coulter is a knife or revolving disk which is fixed so that its point clears the point of the share.
In the disk plough, which is built both as a riding and a walking plough, the essential feature is the substitution of a concavo convex disk, pivoted on the plough beam, for the mould-board and share of the ordinary plough.
This disk is carried on an axle inclined to the line of draught, and also to a vertical plane.
As the machine is drawn forward the disk revolves and cuts deeply into the ground, and by reason of its inclination crowds the earth outwards and thus turns a furrow.
A scraper is provided to keep the disk clean and prevent sticking.
Disk ploughs are unsuitable for heavy sticky soils and for stony land, but may be used with effect on stubbles and on land in a dry hard state.
It consists of a number of tubes mounted vertically on a horizontal circular disk which rotates about a vertical axis in a cylindrical vessel.
This vessel has two tubulures: through one the end of the condenser projects so as to be over one of the receiving tubes; the other leads to the pump. By rotating the disk the tubes may be successively brought under the end of the condenser.
In this way was formed a broad disk of earth, floating on the circumambient air.
In the ectoparasitic Trematodes this post-oral sucker is a complex disk placed near the hinder end and provided With suckerlets, hooks and a musculature arising from a special skeleton.
3) the terms by which these parts are designated: The skin does not form eyelids; but the epidermis passes over the eye, forming a transparent disk, concave like the glass of a watch, behind which the eye moves.
Even if a charged and insulated conductor, such as an open canister or deep cup, is not perfectly closed, it will be found that a proof-plane consisting of a small disk of gilt paper carried at the end of a rod of gum-lac will not bring away any charge if applied to the deep inside portions.
The above expressions for the capacity of an ellipsoid of three unequal axes are in general elliptic integrals, but they can be evaluated for the reduced cases when the ellipsoid is one of revolution, and hence in the limit either takes the form of a long rod or of a circular disk.
In the other extreme case the oblate spheroid becomes a circular disk when e = i, and then the capacity C2 = 2a17r.
This last result shows that the capacity of a thin disk is 2/7r =1/1.571 of that of a sphere of the same radius.
pp. 137 and 347) determined in 1773 experimentally that the capacity of a sphere was 1.541 times that of a disk of the same radius, a truly remarkable result for that date.
The metal slips are so placed that, as the disk revolves, the middle brush, connected to one terminal of the condenser C, is alternately put in conductive connexion with first one and then the other outside brush, which are joined respectively to the battery B and galvanometer G terminals.
In addition there is a small glandular disk, which assumes different shapes in FIG.
of the XVIIIth Egyptian dynasty, who in the latter years of his reign chose to be known as Akhenaton, "the glory of the solar disk."
The tsien is a round disk of copper alloy, with a square hole punched through the centre for stringing.
Savary expresses preference for this second plan, and makes the pertinent remark that in both these models " the rays of red light in the two solar images will be next to each other, which will render the sun's disk more easy to be observed than the violet ones."
The disk, 30 with its small projecting handle enables the 2 segments of the divided object to be moved rapidly or with any required delicacy relative to each other.
The disk 32 operates the wire gauze screens for equalizing the brightness of the two stars under observation.
If measures are made by placing the image of a star in the centre of the disk of a planet, the observer may have a tendency to do so systematically in error from some acquired habit or from natural astigmatism of the eye.
The Ionian geographers looked on the circular disk of the habitable world as surrounded by a mighty stream named Oceanus, the name of the primeval god, father of gods and men, and thus the bond of union between heaven and earth.
In the North Sea north of the Dogger Bank, for instance, the disk is visible in calm weather to a depth of from io to 16 fathoms, but in rough weather only to 62 fathoms. Knipovitch occasionally observed great transparency in the cold waters of the Murman Sea, where he could see the disk in as much as 25 fathoms, and a similar phenomenon has often been reported from Icelandic waters.
Luksch found the disk visible as a rule to from 22 to 27 fathoms, and off the Syrian coast even to 33 fathoms. In the open Atlantic there are `great differences in transparency; Kriimmel observed a 6 ft.
disk to depths of 31 and 36 fathoms in the Sargasso Sea, but in the cold currents of the north and also in the equatorial current the depth of visibility was only from zi to 162 fathoms. to the tropical parts of the Indian and the Pacific Oceans the depth of visibility increases again to from 20 to 27 fathoms. Some allowance should be made for the elevation of the sun at the time of observation.
Mill has shown that in the North Sea off the Firth of Forth the average depth of visibility of a disk in the winter half-year was 4; fathoms and in the summer half-year 62 fathoms, and, although the greater frequency of rough weather in winter might tend to obscure the effect, individual observations made it plain that the angle of the sun was the main factor in increasing the depth to which the disk remained visible.
Schott gives the following as the result of measurements of transparency by means of a white disk at 23 stations in the open ocean, where quantitative observations of the plankton under i square metre of surface were made at the same time.
This agent has been applied in various ways, in machines which either imitate the action of the collier by cutting with a pick or make a groove by rotating cutters attached to an endless chain or a revolving disk or wheel.
For flat ropes the drum or bobbin consists of a solid disk, of the width of the rope fixed upon the shaft, with numerous parallel pairs of arms or horns, arranged radially on both sides, the space between being just sufficient to allow the rope to enter and coil regularly upon the preceding lap. This method has the advantage of equalizing the work of the engine throughout the journey, for when the load is greatest, with the full cage at the bottom and the whole length of rope out, the duty required in the first revolution of the engine is measured by the length of the smallest circumference; while the assistance derived from gravitating action of the descending cage in the same period is equal to the weight of the falling mass through a height corresponding to the length of the largest lap, and so on, the speed being increased as the weight diminishes, and vice versa.
In Koepe's method the drum is replaced by a disk with a grooved rim for the rope, which passes from the top of one cage over the guide pulley, round the disk, and back over the second guide to the second cage, and a tail rope, passing round a pulley at the bottom of the shaft, connects the bottoms of the cages, so that the dead weight of cage, tubs and rope is completely counterbalanced at all positions of the cages, and the work of the engine is confined to the useful weight of coal raised.
In one of the best-known examples, the Zollern colliery in Westphalia, the Koepe system is used, the winding disk being driven by two motors of 1200 H.P. each on the same shaft.
The torque required to hold the casing still against the action of the disk measures the torque exerted by the shaft to which the disk is keyed.
This device consists of a roller of radius r, pressed into contact with a disk.
The two are carried on a common frame, so arranged that a change in form of the spring causes a relative displacement of the disk and roller, the point of contact moving radially from or towards the centre of the disk.
The angular displacement, 0, of the disk is made proportional to the displacement, s, of the point of application of the force by suitable driving gear.
If do is the angular displacement of the roller corresponding to displacements, dO of the disk, and ds of the point of application of P, a, and C constants, then d4) = x _ ¢Pds = C.Pds, and therefore 4) = C f 82 Pds; that is, the angular displacement of the roller measures the work done during the displacement from s 1 to s 2 .
The block A carries the disk D, B carries the roller R and counting gear.
A Morin disk and roller integrator is connected with the apparatus, so that the work done during a journey may be read off.
This is suggested by the recent discovery at Phaestos in Crete of a disk with evidence for a native script; see A.
Shield sights were introduced for disappearing mountings to admit of continuous laying for line, and a disk engraved for yards of range duly corrected for height, and called an " elevation indicator," replaced the index plate and reader.
The king bird of paradise (Cicinnurus regius) is one of the smallest and most brilliant of the group, and is specially distinguished by its two middle tail feathers, the ends of which alone are webbed, and coiled into a beautiful spiral disk of a lovely emerald green.
They slide down the table and enter a narrow passage where only one can pass at a time, jamming being prevented by the joggling action of an eccentric rotating disk at the entrance to the passage.
The coins are then gripped by a pair of india-rubber driving wheels, which force them past the rim of a thin disk with notches in its edge to fit the coins.
As the disk is thus made to revolve, the coins are pushed forward, and falling down a shoot are received in a bag.
We may obtain an excellent representation of the motion of the layers of air in a train of sound waves by means of a device due to Crova and known as " Crova's disk."
A small circular disk at one end of a torsion arm formed part of a solid wall, but was free to move through a hole in the wall slightly larger than the disk.
A small metal disk was attached to the centre of the membrane and connected to earth by a fine wire.
A metal contact-piece adjustable by a screw could be made to just touch a point at the centre of the disk.
When the wave travelled to the receiver it pushed back the disk from the contact-piece, and this break, too, was recorded.
Seebeck (1805-1849) is the simplest form of apparatus thus designated, and consists of a large circular disk mounted on a central axis, about which it may be made to revolve with moderate rapidity.
This disk is per- Siren.
forated with small round holes arranged in circles about the centre of the disk.
The disk being started, then by means of a tube held at one end between the lips, and applied near to the disk at the other, or more easily with a common bellows, a blast of air is made to fall on the part of the disk which contains any one of the above circles.
Hence the note produced with any given circle of holes rises in pitch as the disk revolves more rapidly; and if, the revolution of the disk being kept as steady as possible, the tube be passed rapidly across the circles of the first series, a series of notes is heard, which, if the lowest be denoted by C, form the sequence C, C1, El, G1, C2, &c. In like manner, the first circle in which we have two sets of holes dividing the circumference, the one into say 8 parts, and the other into Io,.
A still simpler form of siren may be constituted with a good spinning-top, a perforated card disk, and a tube for blowing with.
There was one opening in its disk, and through this was viewed the pendulum of a clock beating seconds.
Disk piles have been used in sand.
The thin disk of mercury is therefore traversed perpendicularly by lines of magnetic force when the magnet is excited.
The current to be measured is passed through the coils of the electromagnet, then enters the mercury disk at the centre, flows through it radially in all directions, and emerges at the periphery.
In one of these a copper disk, called the brake disk, revolves, and in the other a copper armature disk.
The latter is slit radially, and the magnetic field is so arranged that it perforates each half of the disk in opposite directions.
The current to be measured passes transversely across the disk and causes it to revolve in the magnetic field; at the same time the copper brake, geared on the same shaft, revolves in the field and has local or eddy currents produced in it which retard its action.
The driving force is balanced against a retarding force produced by the rotation of a copper disk fixed on the armature shaft, which rotates between the poles of a permanent magnet.
Induced or eddy currents are thus created in the copper disk, and the reaction of these against the magnetic field offers a resistance to the rotation of the disk.
Hence when a current is passed through the meter, the armature rotates and increases its speed until the driving force is balanced against the retarding force due to the eddy currents in the copper brake disk.
It consists of a disk of aluminium, the axis of which is geared to a counting mechanism and which runs between the poles of permanent magnets that create eddy currents in it and therefore exert a retarding force.
In proximity to the upper side of the disk is placed a coil of wire having an iron core, which is a shunt coil, the ends of the coil being connected to the terminals of the supply mains.
Under the disk are two other coils which areTplaced in series with the supply.
Since the eddy currents induced in the disk are 90 degrees in phase behind the inducing field, the eddy currents produced by the main coil are in step with the magnetic field due to the shunt coil, and hence the disk is driven round by the revolution due to the action of the shunt coil upon the induced currents in the disk.
Hence the disk will be accelerated until the driving force is balanced by the retarding force due to the induced currents created in the disk by the permanent magnets.
According to the solar theory, Sisyphus is the disk of the sun that rises every day and then sinks below the horizon.
Seps, of the Mediterranean countries and south-western Asia, has a transparent disk on the lower eyelid which is movable; limbs very short or reduced to mere vestiges.
5) made of brass, with a plane base, of equal height and diameter; which when filled to the brim, as determined by a plane glass disk, contains io lb weight of water at t = 62° F.B.
Six disk weights from Carthage (44) show 126.
The stomach may be situated in the disk, or may be drawn out into the base of the manubrium, so that the disk is occupied only by the radial canals.
A rotifer may be regarded as typically a hemisphere or half an oblate spheroid or paraboloid with a mouth somewhere on the flat end ("disk" or "corona"), which bears a usually double ciliated ring, the outer zone the "cingulum," and inner the "trochus".
The apical end of the rotifer usually narrows suddenly beyond the curve of the gut and the cloacal aperture to form the foot of pseudopodium which ends in an organ of attachment, a pair of movable toes, each with the opening of a cement-gland (gl) at its tip. Thus for orientation we place the rotifer like the cuttle-fish, head downwards: the ciliated disk is basal or oral, proximal to the rest of the animal, the foot is apical, and the brain and cloacal aperture are anterodorsal.
We may suppose that primitively the mouth was seated in the centre of a funnel-shaped disk, surrounded by a double wreath.
In Flosculariaceae the trochus is a horseshoe-shaped ridge deep down in the funnel-shaped disk.
i, Simple disk of Microcodon; 2, bdelloid disk of Rotifer and of most Melicertids showing dorsal gap; 3, disk of Hydatina, with lobed ridges in the groove, bearing vibratile styles (membranelles); 4, disk of Melicerta ringens and M.
conifera; the star represents the ciliated cup connected by ciliated depressions with the groove; 5, disk of Conochilus, like the Bdelloid, but with mouth antero-dorsal, the gap postero-ventral; 6, disk of Stephanoceroscingulum broken up into setiferous lobes, groove a naked funnel, trochus a horseshoe-shaped ridge, mouth central.
The trochus forms the powerful currents for locomotion, and for the supply of food material, while the cingulum produces a local current round the upper rim of the corona to bring the food particles direct to the mouth, which is displaced through a postero-ventral gap in the trochus to lie behind the disk, just as occurs in the more specialized Ciliata.
There is a dorsal interruption to the disk, in volving both trochus and cingulum and groove in this case the two halves of the disk may be developed in lobes, flower-shaped in Melicerta ringens, but often rounded and projecting like kettledrums. These give a strong impression of two crown wheels revolving in the same sense.
7) possess a pair of aurioles, great eversible ciliated pouches a little above the disk, utilized in swimming.
On either side is attached a dorsolateral and ventro-lateral appendage, each with a fan-like plumose termination consisting of compound hairs or setae, found elsewhere only among arthropods (q.v.); each of these is moved by muscles running upwards towards the neck and arising immediately under the trochal disk, the inferior ventro-lateral pair also presenting muscles which form a girdle in the hind region of the body.
ment and of the struc ture of the disk to their identification of "trochus" and "cingulum" with the preoral and postoral wreaths of the trochophore larva.
He notably regards an oblique disk with uniform ciliation as primitive, a view which we cannot adopt.
Bdelloidaceae; foot with two toes and accessory spurs or a simple perforated disk; body telescopic at either end, with an antero-dorsal proboscis ending in a ciliate cup and bearing the proximal antenna; corona usually bilobed, very wheel-like.
(iv.) Trophi uncinate: Flosculariaceae; disk a contractile cup, often lobed, the cingulum of long vibratile cilia, of very long motionless bristles or absent, rarely with an outer zone of fine cilia.
Bodywall usually traversed by a network of canals serving by their contraction to expand the disk.
Males and larvae with a ciliated pedal cup and a simple ciliated disk.
(a) Floscularidae; tubicolous, with a lobed disk, bearing stiff or vibratile setae.
Illoricata, cuticle soft; ciliated exsertile auricles above the disk sometimes present.
Body elongated with a narrow neck above the disk; foot ending in a terminal perforated disk.
During this time the illusion of a wheel or wheels produced by the ciliary action of the disk had puzzled all observers.
Both bear their round or ovoid male catkins at the ends of the slender terminal branchlets; the ovoid cones, either terminal or on short lateral twigs, have thick woody scales dilated at the extremity, with a broad disk depressed in the centre and usually furnished with a short spine; at the base of the scales are from three to seven ovules, which become reversed or partially so by compression, ripening into small angular seed with a narrow wing-like expansion.
together and having a quadrantal shape, that is, approximately the shape of a quarter of a circular disk.
The foot is commonly a simple cylindrical or ploughshare-shaped organ, used for boring in sand and mud, and more rarely presents a crawling disk similar to that of Gastropoda; in some forms it is aborted.
The type form is the Caucasian species roseum of botanists, hardy perennial, with finely cut leaves and large flower heads, having a ray of deep rosecoloured ligulate florets surrounding the yellow centre or disk.
The peculiarity of the instrument consists in the stream of water, as it enters the hydrometer chamber, being made to impinge against a disk of metal, by which it is broken into drops, thus liberating the steam, which would otherwise disturb the instrument.
When the waste contains any large percentage of worm or chrysalis, it is taken to a " cocoon beater," a machine which has a large revolving disk on which the silk is put, and while revolving slowly is beaten by a leather whip or flail, which loosens the silk and knocks out the wormy matter.
The method adopted consisted in photographing the spectrum on a film which was kept in rapid motion by being attached to the front of a rotating disk.
Royds made with the same rotating disk, but with improved optical appliances.
The card or "fly," formerly made of cardboard, now consists of a disk either of mica covered with paper or of paper alone, but in all cases the card is divided into points and degrees as shown in fig.
silk threads to a central disk of aluminium, in the centre of which is a round hole designed to receive an aluminium cap with a highly polished sapphire centre worked to the form of an open cone.
The card is a mica disk, either painted as in fig.
Remains of sculpture, engraved bronzes and gems, show clearly the source to which the Phoenician artists went for inspiration; for example, the uraeus-frieze and the winged disk, the ankh or symbol of life, are Egyptian designs frequently imitated.
Aristotle saw in the temple of Hera at Olympia a bronze disk, recording the traditional laws of the festival, on which the name of Lycurgus stood next to that of Iphitus, king of Elis.
Whatever may have been the age of the disk itself, the relation which it indicates is well attested.
&Aces, a threshing-floor, and afterwards applied to denote the disk of the sun or moon, probably on account of the circular path traced out by the oxen threshing the corn.
The early larval stage of the " Lobster Moth " (Stauropus fagi), for example, presents a general resemblance, due to a combination of shape, colour, attitude and movements, to black ants, the swollen head and the caudal disk with its two tentacles representing respectively the abdomen and antenna-bearing head of the model.
He supposed the sun to be a disk of glass which reflects the light of the universe.
so); on the contrary, he conceived it to be a flat disk, and in this supposition he was followed by most of his successors in the Ionian schools, including Anaxagoras.
The spectroscope is then moved parallel to itself, admitting to the collimator slit light from all parts of the sun's disk.
Photographs of the solar disk, taken with the H or K line, show extensive luminous clouds (flocculi) of calcium vapour, vastly greater in area than the sun-spots.
Brachycome iberidifolia: half-hardy, i ft., blue or white with dark disk.
Calliopsis or Coreopsis Drummondii: hardy, I to 2 ft., golden yellow with red disk.
Helianthus cucumerifolius: hardy, 3 to 4 ft., golden yellow, black disk; branching, free and bold without coarseness.
Sphenogyne speciosa: half-hardy, i ft., orange-yellow, with black ring around the disk.
The flowerheads have a dark-coloured elevated disk.
golden-yellow with dark chocolate disk, the flower-heads 2 to 3 in.
speciosa, 2 to 3 ft., orange-yellow with blackish-purple disk, the flower-heads 3 to 4 in.
speciosa, I to 2 ft., is a showy composite, of easy culture in good garden soil; it produces large corymbs of flowerheads, with numerous narrow blue ray-florets surrounding the yellow disk.
Let A and C be two fixed disks, and B a disk which can be brought at will within a very short distance of either A or C. Let us suppose all the plates to be equal, and let the capacities of A and C in presence of B be each equal to p, and the coefficient of induction between A and B, or C and B, be q.
In front of them a disk of ebonite or glass, having carriers of metal fixed to its edge, was rotated by a winch.
Each disk carried two strips of tin-foil extending nearly over a semi-circle, and there were two field plates, one behind each disk; one of the plates was P > P positively and the other negatively electrified.
In one form the Holtz machine consisted of a glass disk mounted on a horizontal axis F (fig.
Close behind this disk was fixed another vertical disk of glass in which were cut two windows B, B.
On the side of the fixed disk next the rotating disk were pasted two sectors of paper A, A, with short blunt points attached to them which projected out into the windows on the side away from the rotating disk.
On the other side of the rotating disk were placed two metal combs C, C, which consisted of sharp points set in metal rods and were each connected to one of a pair of discharge balls E, D, the distance between which could be varied.
To start the machine the balls were brought in contact, one of the paper armatures electrified, say, with positive electricity, and the disk set in motion.
Thereupon very shortly a hissing sound was heard and the machine became harder to turn as if the disk were moving through a resisting medium.
The action of the machine is as follows: Suppose one paper armature to be charged positively, it acts by induction on the right hand comb, causing negative electricity to issue from the comb points upon the glass revolving disk; at the same time the positive electricity passes through the closed discharge circuit to the left comb and issues from its teeth upon the part of the glass disk at the opposite end of the diameter.
The charges thus deposited on the glass disk are carried round so that the upper half is electrified negatively on both sides and the lower half positively on both sides, the sign of the electrification being reversed as the disk passes between the combs and the armature by discharges issuing from them respectively.
The neutralizing conductors for each disk are placed at right angles to each other.
3), while their plungers are connected to a disk crank which rotates above the point 0, which is the centre of the main crank; 0 S being the crank length or half stroke of the engine, any variation in its length will vary the power of the engine and at the same time the quantity of water used.
Hall proposed to overcome this difficulty by coating the plate thickly with copper on both sides, and deducing the difference of temperature between the two surfaces of junction of the iron and the copper from the thermo-electric force observed by means of a number of fine copper wires attached to the copper coatings at different points of the disk.
The following is an analysis of the results obtained, showing the number of times the different grades were reached: - On one or two occasions at Jan Mayen auroral light is described as making the full moon look like an ordinary gas jet in presence of electric light, whilst rays could be seen crossing and brighter than the moon's disk.
The numerous stamens surround the ovary, which is composed of 4 to 16 carpels and is surmounted by a flat or convex rayed disk bearing the stigmas.
His consort was sometimes called Amaune (feminine of Amun), but more usually mother ": she was human-headed, wearing the double crown of Upper and Lower Egypt, and their son was Khons (Chon or Chons), a lunar god, represented as a youth wearing the crescent and disk of the moon.
I) may be on the top of a small rod r, fixed at its lower end by plaster of Paris in a watch S glass w, and carrying a disk or sphere of lead at 1.
The new deity was a personification of the suns disk.
The stone mace head was a sharp-edged disk (3), in the prehistoric from 3140 sequence date; of the pear shape (4) from S.D.
The greatly elongated head is set on a short thick neck, and at the extremity of the snout is a disk in which the nostrils open.
libra, a balance), a slow oscillation, as of a balance; in astronomy especially the seeming oscillation of the moon around her axis, by which portions of her surface near the edge of the disk are alternately brought into sight and swung out of sight.
Originally like Marduk a solar deity with the winged disk - the disk always typifying the sun 8 - as his symbol, he becomes as Assyria develops into a military power a god of war, indicated by the attachment of the figure of a man with a bow to the winged disk.
In Se p tember of that year he discovered that the force required for the rotation of a copper disk becomes greater when it is made to rotate with its rim between the poles of a magnet, the disk at the same time becoming heated by the eddy or "Foucault currents" induced in its metal.
If a circular disk is wrought into a hemisphere and the attempt is made to hammer the edges round, crumpling must occur.
Notwithstanding this difference in the brightness of the objects, we were able with this reflecting telescope to see whatever we have hitherto discovered with the Huygenian, particularly the transits of Jupiter's satellites and their shadows over his disk, the black list in Saturn's ring, and the edge of his shadow cast on his ring.
The Torque Was Measured By Weights 0 And P Suspended By Silk Ribbons Passing Over The Pulleys N And Round The Disk Kl.
how to place a plane quadrilateral of given form so that its geometric shadow may be a square; how to place an elliptic disk, with a small hole in it, so that the shadow may be circular with a bright spot at its centre, &c.
r represents the shadow of a circular disk cast by four equal luminous points arranged as the corners of a square FIG.
the disk being large enough to admit of a free overlapping of the separate shadows.
The separate shadows are circular, if the disk is parallel to the screen.
Hence the illumination of the screen by the light passing through the hole is precisely what would be cut off by a disk which fits the hole, and the complement of fig.
Thus a M circular disk projected under gravity in a vertical plane spins Fic. 7~.
For a homogeneous sphe:e this ratio is ~, for a uniform circular cylinder or disk ~, for a circular hoop or a thin cylindrical shell 4.
Again, take the case of a circular disk rolling in steady motion on a horizontal plane.
The centre 0 of the disk is supposed to describe a horizontal circle of Mg~ j~ radius c with the constant angular II velocity, &, whilst its plane pre II serves a constant inclination 0 to 7/ the horizontal.
about the horizontal diameter of the disk, which corresponds to 013 in fig.
a sin U Mga cos 0, where a is the radius of the disk.
Conical or Bevel and Disk WheelsFrom Principles III.
constant; the line of contact is constant in position, and the rolling surfaces of the wheels are regular circular cones (when they are called bevel wheels); or one of a pair of wheels may have a flat disk for its rolling surface, as W2 in fig.
98, in which case it is a disk wheel.
Eccentric.An eccentric circular disk fixed on a shaft, and used to give a reciprocating motion to a rod, is in effect a crank-pin of sufficiently large diameter to surround the shaft, and so to avoid the weakening of the shaft which would arise from bending it so as to form an ordinary crank.
130), attached to a truly turned disk, be rotated by the shaft OX, and conceive that the shaft is held in a bearing at one point, 0.
To take a simple case, suppose a shaft supported on two bearings to carry a disk of weight W at its centre, I and let the centre of gravity of the disk be at a distance e from the axis of rotation, this small distance being due to imperfections of material or faulty construction.
polnatorhinus (often incorrectly spelt pomarinus), about the size of a common gull, Larus canus, and presenting, irrespective of sex, two very distinct phases of plumage, one almost wholly sooty-brown, the other particoloured - dark above and white on the breast, the sides of the neck being of a glossy straw-colour, and the lower part of the neck and the sides of the body barred with brown; but a singular feature in the adults of this species is that the two median tail-feathers, which are elongated, have their shaft twisted towards the tip, so that in flight the lower surfaces of their webs are pressed together vertically, giving the bird the appearance of having a disk attached to its tail.
Barlow, Sturgeon and others then showed that a copper disk could be made to rotate between the poles of a horseshoe magnet when a current was passed through the disk from the centre to the circumference, the disk being rendered at the same time freely movable by making a contact with the circumference by means of a mercury trough.
One form which this experiment took was that of rotating a copper disk between the poles of a powerful electric magnet.
He then found that a conductor, the ends of which were connected respectively with the centre and edge of the disk, was traversed by an electric current.
Faraday's copper disk rotated between the poles of a magnet, and producing thereby an electric current, became the parent of 1 See also his Submarine Telegraphs (London, 1898).
It works in conjunction with the disk and scroll, the cones, or the expanding pulley, to impart an intermittingly variable speed to the bobbin (each layer of the bobbin has its own particular speed which is constant for the full traverse, but each change of direction of the builder is accompanied by a quick change of speed to the bobbin).
The builder, which receives its motion from the disk and scroll, from the cones, or from the expanding pulley, has also an intermittingly variable speed.
A form of attracted disk absolute electrometer was devised by A.
C is an insulated disk over which is suspended another disk attached to the arm of a balance.
A weight is put in the opposite scale pan and a measured charge of electricity is given to the disk C just sufficient to tip over the balance.
- Snow-Harris's Disk Electrometer.
3) is a plane disk of metal called the guard plate, fixed to the inner coating ?i??!?L...
If then another horizontal disk G is placed over the disk H H and a difference of potential made between G and H H, the movable aluminium trap door F will be attracted by the fixed plate G.
Matters are so arranged by giving a torsion to the wire carrying the aluminium disk F that for a certain potential difference between the plates H and G, the movable part F comes into a definite sighted position, which is observed by means of a small lens.
Since the distribution of electricity may be considered to be constant over the surface S of the attracted disk, the mechanical force f on it is given by the expression,' f S(V - v)2 8 ird2 where d is the distance between the two plates.
If this distance is varied until the attracted disk comes into a definite sighted position as seen by observing the end of the index through the lens, then since the force f is constant, being due to the torque applied by the wire for a definite angle of twist, it follows that the difference of potential of the two plates varies as their distance.
There is a certain fixed guard disk B having a hole in it which is loosely occupied by an aluminium trap door plate, shielded by D and suspended on springs, so that its surface is parallel with that of the guard plate.
First one and then the other conductor is connected with the electrode of the lower or movable plate, which is moved by the screw until the index attached to the attracted disk shows it to be in the sighted position.
If W is the weight required to depress the attracted disk into the same sighted position when the plates are unelectrified and g is the acceleration of gravity, then the difference of potentials of the conductors tested is expressed by the formula V - V'=(d - d') /87 W where S denotes the area of the attracted disk.
If the gold-leaf is unelectrified, it is not acted upon by the two plates placed at equal distances on either side of it, but if its potential is raised or lowered it is attracted by one disk and repelled by the other, and the displacement becomes a measure of its potential.
a replenisher or rotating electrophorus, by means of which the charge of the Leyden jar which forms the enclosing vessel can be increased or diminished, and also a small aluminium balance plate or gauge, which is in principle the same as the attracted disk portable electrometer by means of which the potential of the inner coating of the Leyden jar is preserved at a known value.
In a plane containing the image point of one colour, another colour produces a disk of confusion; this is similar to the confusion caused by two " zones " in spherical aberration.
For infinitely distant objects the radius of the chromatic disk of confusion is proportional to the linear aperture, and independent of the focal length (vide supra," Monochromatic Aberration of the Axis Point "); and since this disk becomes the less harmful with an increasing image of a given object, or with increasing focal length, it follows that the deterioration of the image is proportional to the ratio of the aperture to the focal length, i.e.
Now these forces are balanced by the external force which acts on the disk ACB, which we may call F.
Now let us consider a cylindric film contained between two equal fixed disks A and B, and let a third disk, C, be placed midway between.
If AC and CB are each less than half the circumference of a disk the pressure on C will increase on the side of A and diminish on the side of B.
But if the length of the cylindric film is greater than its circumference, and if we suppose the disk C to be placed midway between A and B, and to be moved towards A, the pressure on the side next A will diminish, and that on the side next B will increase, so that the resultant force will tend to increase the displacement, and the equilibrium of the disk C is therefore unstable.
Magnus employed a rotating mirror, and also a rotating disk from which a fine slit was cut out.
This consisted of a paf3Sos or bronze rod; a 7rM6aTcy, a small disk or basin, resembling a scale-pan; a larger disk (XEKavis); and (in 1 The epithet Kara&ros (let down) may refer to the rod, which might be' raised or lowered as required; to the lower disk, which might be moved up and down the stem; to the moving up and down of the scales, in the supposed variety of the game mentioned below.
The first specimen of the apparatus found at Perugia resembles a candelabrum on a base, tapering towards the top, with a blunt end, on which the small disk (found near the rod), which has a hole near the edge and is slightly hollow in the middle, could be balanced.
At about a third of the height of the rod is a large disk with a hole in the centre through which the rod runs; in a socket at the top is a small bronze figure, with right arm and right leg uplifted.
In the second specimen there is no large disk, and the figure is holding up what is apparently a rhyton or drinking-horn.
In the first the smaller disk was placed on the top of the rod, and the object of the player was to dislodge it with a cast of the wine, so that it would fall with a clatter on the larger disk below.
In the second (as in the third) the bronze figure was used; the smaller disk was placed above the figure, upon which it fell when hit, and thence on to the larger disk below.
In the third, there was no smaller disk; the wine was thrown at the figure, and fell on to the larger disk underneath.
Also from ancient times Naturally, the introduction of the pendant seal invited an impression on the back as well as on the face of the disk of wax or other material employed.
E, Young ephyra just liberated, showing the eight bifurcate arms of the disk ' and the interradial single gastral filaments.
JR == R 3, Adradial lobe of the disk.
In Siphonopodiidae it ends in a disk with papillated margins, and in Pulsellum there is a filament in the centre of the disk.
Foot expanded distally into a symmetrical disk with a crenate edge or simple and vermiform without well-developed lateral processes; shell often contracted towards the anterior aperture.
Siphonodentalium: foot ending in a median disk without a median appendage.
Pulsellum: terminal disk of foot with a median appendage.
- Antlers rounded, usually with five or more tines, generally including a bez (second), and always a trez (third); coat of adult generally unspotted, with a large lightcoloured disk surrounding the tail; young, spotted.
Besides granulations the sun's disk shows, as a rule, one or more spots or groups of spots.
The largest spots are easily seen by the naked eye, if the brilliancy of the disk is veiled; the umbra may be many - ten or more - diameters of the earth in breadth.
They are carried across the disk by the sun's rotation, partaking in the equatorial acceleration; they also show marked displacements of their own, whether with, or relative to, the neighbouring photosphere does not appear; at the beginning of their life they usually outrun the average daily rotation appropriate to their latitude.
Its absorptive effects upon the radiations of the inner photosphere can be readily traced progressively from the centre to the rim of the sun's disk, and it has been measured as a whole by Langley, W.
The entries in the table on following page express the reduction of intensity for different wave-lengths X, when the slit is set at distances yXradius from the centre of the disk.
Besides this the spectrum shows very many differences from the mean spectrum of the disk, the interpretation of which is at present far from clear.
The radiation from a spot changes little as it approaches the sun's limb; in fact Hale and Adams find that the absorption from the limb itself differs from that of the centre of the disk in a manner exactly resembling that from a spot, the same lines being strengthened or weakened in the same way, though in much less degree, with, however, one material exception: if a line is winged in the photosphere the wings are generally increased in the spot, but on the limb they are weakened or obliterated.
The helium formations do not reach the sun's limb, and it is another puzzling detail that the spectrum of the disk shows no absorption line of anything like an intensity to correspond with the emission line of helium in the chromosphere.
Consider the rays which meet the eye (at unit distance) at an angle d from the centre of the sun's disk; in their Theory previous passage through the partially translucent por.
Apart then from absorption there will be a discontinuous change in brightness in the apparent disk at that value of the angular radius d which corresponds to tangential emission from the upper lever r' of this mirage-forming region.
Hence if the sun's diameter were measured through differently coloured screens, the violet disk must appear greater than the red.
Whatever be the subsequent method of reduction, the instant is required when the planet's disk is in internal contact with that of the sun; but after contact has plainly passed it still remains connected with the sun's rim by a " black drop," with the result that trained observers using similar instruments set up a few feet from one another sometimes differed by half a minute of time in their record.
The disk of Mars and his colour are certain disadvantages, and Gill.
The planet showed a stellar disk varying in magnitude from 9 to 12.
8 the weight on the platform is transferred by levers to the vertical steel band, A, which is wrapped round an arbor on the axle of the disk - wheel, B, to which is rigidly attached the toothed segment, C. The weight, D, is rigidly attached to the axle of the wheel, B, and the counterbalance, E, is hung from the wheel, B, by means of a cord wrapped round it.
The upper end of this rod is formed into a loop, and this loop pulls upon a knife-edge which is fixed to a short lateral arm rigidly attached to a vertical disk, and this disk turns in bearings formed in the frame of the machine.
The manner in which the balance of the load is weighed is as follows: Near the bottom of the vertical leg from the goods-pan, a projecting piece is rigidly attached to it, and as the pan descends with the balance of the load this piece pulls by a hook on a thin band of steel, which llIwwim is led upwards and wraps round the surface of a disk to which it is firmly secured.
This disk rotates by rocking on a pair of knife-edges whose bearings are rigidly attached to the frame.
The disk carries a weighted brass cylinder rigidly attached to it, which is pulled into an oblique position by the steel band until equilibrium is established.
And the disk also carries the index arm which plays past the vertical face of the chart, and indicates the weight and price up to 2-lb weight.
The disk also carries a second and corresponding index arm which indicates the weight on the purchaser's side of the machine.
Next the ratchet wheel is a disk which is keyed on to the shaft.
The ratchet wheel and the disk are automatically connected by clutch mechanism in order to effect the rotation of the brushes.
Each mesentery is attached by its upper margin to the peristome, by its outer margin to the body-wall, and by its lower margin to the basal disk.
Other mesenteries, called incomplete, are not attached to the stomodaeum, and their internal margins are free from the peristome to the basal disk.
(Af ter von Koch.) formed, the endoderm of the basal disk lying above the basal plate is raised up in the form of radiating folds.
In some species young examples have been met with in which the nema ends above in a small membranous disk, which has been interpreted as an organ of attachment to the underside of floating bodies, probably sea weeds, from which the young polypary hung suspended.
Io, Young Dictyograptus, with primary disk.
14, Dichograptus octobrachiatus, with central disk.
In the Dendroidea, as a rule, the polypary is non-symmetrical in shape and tree-like or shrub-like in habit, with numerous branches irregularly disposed, and with a distinct stem-like or short basal portion ending below in root-like fibres or in a membranous disk or sheet of attachment.
The Graptoloidea have also been regarded by some as benthonic organisms. A more prevalent view, however, is that the majority were pseudo-planktonic or drifting colonies, hanging from the underside of floating seaweeds; their polyparies being each .suspended by the nema in the earliest stages of growth, and, in later stages, some by the nemacaulus, while others became adherent above by means of a central disk or by parts of their dorsal walls.
aboral) surface of the disk.
- Eleutherozoa with a depressed stellate body composed of a central disk, whence radiate five or more rays; this radiate symmetry affects all the systems of organs, including the genital.
- Ambulacrals not yet forming complete vertebrae; plates of disk not yet specialized into mouth, radial or genital shields.
The Silurian genera Eucladia and Euthemon have the rays greatly reduced and merged in the disk, so that the ambulacrals are unseen.
The term is sometimes given incorrectly in architecture to a circular disk carved with a conventional rose, which is found in many early styles, the proper term being rosette.
3 D) consists of a stalk expanding into a peltate disk of hexagonal outline; from the inner surface of the latter six to nine large sporangia hang parallel with the stalk.
by its disk on the 13th of March 1781; two of its satellites, Oberon and Titania, disclosed themselves on the it th of January 1787; while with the giant 48-in.
Hale devised on the same principle the " spectroheliograph," an instrument by which the sun's disk can be photographed in calcium-light by imparting a rapid movement to its image relatively to the sensitive plate; and the method has proved in many ways fruitful.
Papuan weapons are the bow and arrow (in the Fly River region, the north and north-east coasts); a beheading knife of a sharp segment of bamboo; a shafted stone club - rayed, disk shaped or ball-headed (in use all over the island); spears of various forms, pointed and barbed; the spear-thrower (on the Finsch coast); and hardwood clubs and shields, widely differing in pattern and ornamentation with the district of their manufacture.
One is the existence of dark and bright regions, irregular in form, on its surface; the other is the complete illumination of the lunar disk when seen as a crescent, a faint light revealing the dark hemisphere.
The spot which has most frequently exhibited changes in appearance is near the centre of the visible disk, marked on Beer and Madler's map as Linne.
In 1825 he retired from the House of Commons, and the following year settled at Highwood Hill, near Mill Hill, "just beyond the disk of the metropolis."
The heretical worship of the solar disk interrupted the course of Egyptian religion under some reforming kings, but the great and glorious Ramesside Dynasty (XIX.) restored " Orus and Isis and the dog Anubis " with the rest of the semitheriomorphic deities.
The polarizing prism is fixed at the centre of a circular disk, that has a scale on its circumference, which with a fixed vernier determines the positions of the polarizer, for which the bands disappear at the assigned point of the field.
Twice in the year, he observed, they seem to travel across the solar disk in straight lines; at other times, in curves.
The image consists of a diffraction disk from whose form and size certain conclusions may be drawn as to the size and form of the object.
This concentration is most easily produced by sliding or revolving diaphragms. A series of holes of different sizes perforate a revolving disk below the stage plate at an equal radial distance from the axis of the disk, so that the holes can be brought under the preparation in turn, the centre of the diaphragms always being a continuation of the optical axis of the microscope.
The central diaphragm disk keeps away all the light which would otherwise fall directly into the objective, and the open zones send so many oblique rays through the object that they cannot all be taken up by the objective.
In other fine adjustments by means of springs and balance wheels either a micrometer screw is moved (Zeiss), or a curved disk fixed to the balance wheel is turned (Leitz), or an oblique disk arranged more or less in a circle and attached to the balance wheel is revolved (Reichert).
In order to ensure for the eye a central position, there is fixed on the upper end of the tube in place of the eyepiece a disk of pasteboard or metal with an axial hole.
The name itself (= red) and the colour of the cattle suggest the fiery aspect of the disk of the setting sun; further, Heracles crosses Oceanus in the golden cup or boat of the sun-god Helios.
In the American button-bush the heads are globular, in some species of teazel elliptical, while in scabious and in composite plants, as sunflower, dandelion, thistle, centaury and marigold, they are somewhat hemispherical, with a flattened, slightly hollowed, or convex disk.
Under the term disk is included every structure intervening between the stamens and the pistil.
The disk is frequently formed by degeneration or transformation of the staminal row.
In some flowers, as Jatropha Curcas, in which the stamens are not developed, their place is occupied by glandular bodies forming the disk.
In Gesneraceae and Cruciferae the disk consists of toothlike scales at the base of the stamens.
- Flower of Tree waxy lining of the hollow receptacle, Paeony (Paeonia Moutan), as in the rose; or a swelling at the deprived of its corolla, and top of the ovary, as in Umbelliferae, showing the disk in the form in which the disk is said to be of a fleshy expansion (d) ep i gynous.
covering the ovary in Nymphaea (Castalia) and Nelumbium may be regarded as a form of disk.
A number of hairy linear bracts enclose the whole; internal to these occur 12 to 20 crowded pinnate leaves (sporophylls), with their apical portions bent over towards the axis of the flower, the bases of the petioles being fused laterally into a disk surrounding the base of the conical receptacle.
Mr Wieland's researches have, however, demonstrated the existence in flowers of this type of the remains of a disk at the base of the receptacle, between the receptacle and the surrounding bracts, to which staminate leaves were originally attached.
In the point-by-point method the shaft of an alternator, or an alternating current motor driven in step with it, is furnished with an insulating disk having a metallic slip inserted in its edge.
Against this disk press two springs which are connected together at each revolution by the contact of the slip at an assigned instant during the phase of the alternating current.
If the contact springs can be moved round the disk so as to vary the instant of contact, we can plot out the value of the observed instantaneous voltage of the machine or circuit in a wavy curve, showing the wave form of the electromotive force of the alternator.
The process is analogous to the optical experiment of looking at a quickly rotating wheel or engine through slits in a disk, rotating slightly faster or slower than the object observed.
In another form devised by Callendar," a revolving contact disk is placed on the shaft of an alternator, or of a synchronous motor driven by the alternating current under test.
In this case the large vibrating mirror must be oscillated by a current from an alternator, on the shaft of which is a disk of nonconducting material with brass slips let into it and so arranged with contact brushes that in each period of the alternator a contact is made, charging say a condenser and discharging it through the oscillograph.
The first of these resemble an ordinary reverberatory furnace by having a flat bed which, however, has the form of a circular disk mounted on a central shaft, and receives a slow movement of rotation from a water-wheel or other motor, so that every part of the surface is brought successively under the action of the fire, the charge being stirred and ultimately removed by passing under a series of fixed scraper arms placed above the surface at various points.
Its impeccable pedigree comes from the 808, the highest quality compact disk player Meridian has ever built.
Big 5kg disk, faced with fine aluminum oxide abrasive.
accelerometer devices attached, scattered randomly over the surface of a spinning disk.
Includes a high-quality printed vocal score and a compact disk with stereo accompaniments to each piece minus you, the soloist.
accretebsence of jets indicates that the star is not actively accreting material from this disk.
Black hole accretion disk Useful web links A good place to start is Relativity on the WWW.
Clean up your disk Your hard disk will gradually accumulate clutter, in the form of various files which are no longer necessary.
The inward bend of the upper airstream is accompanied by a substantial drop in air pressure just above the disk, sucking it upward.
This is known as your quota allocation and it is used to control the amount of disk space that you have available.
alphanumeric identifiers which web sites transfer to your hard disk.
ampersand files for all these disk drives.
anamorphic transfer which is being done for the disk.
Finally, if the infalling gas has too much angular momentum it cannot form circumstellar disks and all goes into a circumbinary disk.
The large angular momentum in this massive disk leads to turbulence and increased interaction of the constituents.
annular tear / disk prolapse has been ruled out.
annulus of each disk.
In addition the following injuries can occur:- Cervical Disk Prolapse - caused by a rupture of the posterior disk annulus.
The two early votive antiphons Ave Dei and Ave Rosa open the disk and it concludes with one of Tallis's masterpieces Salve Intemerata.
appendix h: Reducing Disk Space Requirements for Executables The program executables are big, and you may want to make them smaller.
Our Galaxy has spiral arms in its disk - these spiral arms are regions of active star formation.
On a new disk, it's better to use BIOS automatic hard disk recognition and say " yes " .
EXTENSION Cont. → Rupture of anterior longitudinal ligament +/- avulsion fracture +/- Disruption of disk space?
That's the bonus of Ian on disk: there's no danger of his voice going AWOL!
The flat disk is transferred onto another, preheated kiln batt which is securely seated on one end of a long metal pole.
bonus disk shows us the all too familiar human side of the cheeky cast.
boot disk virus.
These options include from a simple cylinder to convert standard disk brakes to the fluid type, to a full twin disk system.
The heat thickens and seals the disk wall and reduces inner disk bulge and irritation of the spinal nerve.
Is there some way to disable the disk cache (I assume thats the problem) for the floppy drive?
This displays the speed of reading through the buffer cache to the disk without any prior caching of data.