ClipArt ETC
"Idyia roseola. Seen from the broad side, half natural size. a, anal opening; b, lateral tube; c, circular tube; d, e, f, g, h, rows of paddles." -Parker, 1900

Idyia Roseola

"Idyia roseola. Seen from the broad side, half natural size. a, anal opening; b, lateral tube; c, circular…

"Ambulacral system of a starfish. a, ampullae; ap, Polian vesicles; c, circular canal; m, madreporite; m', madreporic canal; p, tube-feet; r, radial vessels; r', branches to ampullae." -Parker, 1900

Ambulacral System

"Ambulacral system of a starfish. a, ampullae; ap, Polian vesicles; c, circular canal; m, madreporite;…

Isometric of a prism with a semicircular top.

Prism With Semicircular Top

Isometric of a prism with a semicircular top.

Strong dust storms that move in a circular motion. They mostly occur in deserts such as deserts found in these regions: Arabia, Jordan, Syria, Palestine

Simoon Storm

Strong dust storms that move in a circular motion. They mostly occur in deserts such as deserts found…

A straight or slightly curved metallic bar, with teeth n one of its edge, adapted to work into the teeth of a wheel or pinion, for the purpose of converting a circular into a rectilinear motion or vice versa.

Machinery Rack

A straight or slightly curved metallic bar, with teeth n one of its edge, adapted to work into the teeth…

A wheel with pointed and angular teeth, against which a ratchet abuts, used either for converting a reciprocating into a rotatory motion on the shaft to which it is fixed, or for admitting of circular motion in one direction only, as in a winch.

Ratchet Wheel

A wheel with pointed and angular teeth, against which a ratchet abuts, used either for converting a…

"Superficial arteries and nerves of the face and neck. 1, Temporal artery; 2, artery behind the ear; 3, occipital artery; 4, greater occipital nerve; 5, smaller occipital nerve; 6, nerve of the neck; 7, trapezius muscle; 8, clavicular nerves; 9, clavicle; 10, sterno-cleido-mastoid muscle; 11, outer artery of the head; 12, inner artery of the head; 13, salivary gland; 14, nerves of the lower jaw; 15, outer maxillary artery; 16, nerve of the chin; 17, circular muscle of the mouth; 18, greater yoke muscle; 19, nerves below the eye; 20, masseter, or chewing muscle; 21, ear passage; 22, arteries of the forehead; 23; nerves of the forehead; 24, eye-closing muscle; 25, facial artery; 26, facial nerve." -Foster, 1921

Arteries and Nerves

"Superficial arteries and nerves of the face and neck. 1, Temporal artery; 2, artery behind the ear;…

A small cruciferous plant, growing in arid Arabia and Palestine. When full grown and ripe its leaves drop and it becomes rolled up like a ball in the dry season, but opens its branches and seed vessels when it comes in contact with moisture.

Illustration of Roots and Jericho Rose

A small cruciferous plant, growing in arid Arabia and Palestine. When full grown and ripe its leaves…

A circular window, divided into compartments by mullions and tracery radiating from a centre, also called Catharine-wheel, and marigold-window.

Rose Brickwork Window

A circular window, divided into compartments by mullions and tracery radiating from a centre, also called…

"Atoll, a coral reef surrounding a pool of shallow water, usually called a lagoon. The atoll is formed by the building of a coral reef on a circular or nearly circular foundation. It is usually broken in one or more places so that the lagoon is connected with the surrounding waters." -Foster, 1921

Atoll

"Atoll, a coral reef surrounding a pool of shallow water, usually called a lagoon. The atoll is formed…

A diagram of a section of the auditory apparatus. Labels: E, external canal; M, in the middle ear; V, vestibule; SC, semi-circular canals; N, auditory nerve; S, cochlea; ET, Eustachian tube.

Diagram of the Auditory Apparatus

A diagram of a section of the auditory apparatus. Labels: E, external canal; M, in the middle ear; V,…

Karyokinesis. Labels: a, ordinary nucleus of a columnar epithelial cell; B, C, the same nucleus in the stage of convolution; D, the wreath or rosette from; E, the aster, or single star; F, a nuclear spindle the Descemet's endothelium of the frog's cornea; G, H, I, diaster; K, two daughter nuclei.

Karyokinesis

Karyokinesis. Labels: a, ordinary nucleus of a columnar epithelial cell; B, C, the same nucleus in the…

Surface view of an artery from the mesentery of a frog, ensheathed in a perivascular lymphatic vessel. Labels: a, The artery, with its circular muscular coat (media) indicated by broad transverse markings, with an indication of the adventitia outside. 1. Lymphatic vessel: its wall is a simple endothelial membrane.

Surface View of an Artery

Surface view of an artery from the mesentery of a frog, ensheathed in a perivascular lymphatic vessel.…

Ciliary epithelium of the human trachea. Labels: a, layer of longitudinally arranged elastic fibers; b, basement membrane; c, deepest cells, circular in form; d, intermediate elongated cells; e, outermost layer of cells fully developed and bearing cilia.

Ciliary Epithelium

Ciliary epithelium of the human trachea. Labels: a, layer of longitudinally arranged elastic fibers;…

From a section of the lung of a cat, stained with silver nitrate. Labels: A. D., alveolar duct or intercellular passage; S, alveolar septa; N, alveoli or air cells, lined with large flat, nucleated cells, with some smaller polyhedral nucleated cells; M, Unstriped muscular fibers. Circular muscular fibers are seem surrounding the interior of the alveolar duct, and at one part is seen a group of small polyhedral cells continued from the bronchus.

Air Cells from a Cat's Lung

From a section of the lung of a cat, stained with silver nitrate. Labels: A. D., alveolar duct or intercellular…

Diagrammatic representation of the nerves of the alimentary canal. Oe to Rct, the various parts of the alimentary canal from esophagus to rectum: L.V, left vagus, ending in front of stomach; rl, recurrent laryngeal nerve, supplying upper part of esophagus; R.V, right vagus, joining left vagus in esophageal plexus; oe.pl., supplying the posterior part of the stomach , and continues at R'V' to join the solar plexus, here represented by a single ganglion, and connected with the inferior mesenteric ganglion m.gl.: a, branches from the solar plexus to stomach and small intestine , and from the mesenteric ganglia and rami communicantes; r.c., belonging to dorsal nerves from the 6th to the 9th (or 10th); Spl.min., small splanchnic nerve similarly from the 10th and 11th dorsal nerves. These both join the solar plexus, and thence make their way to the alimentary canal; c.r., nerves from the ganglia, &c., belonging to 11th and 12th dorsal and 1st and 2nd lumbar nerves, proceeding to the inferior mesenteric ganglia (or plexus), m.gl., and thence by the hypogastic nerve, n.hyp., and the hypogastric nerve, n.hyp., and the hypogastric plexus, pl.hyp., to the circular muscles of the rectum; 1.r., nerves from the 2nd and 3rd sacral nerves, S.2, S.3 (nervi erigentes) proceeding by the hypogastric plexus to the longitudinal muscles of the rectum.

Nerves of the Alimentary Canal

Diagrammatic representation of the nerves of the alimentary canal. Oe to Rct, the various parts of the…

Hepatic cells and bile capillaries, from the liver of a child three months old. Both figures represent fragments of a section carried through the periphery of a lobule. The red corpuscles of the blood are recognized by their circular contour; vp, corresponds to an interlobular vein in immediate proximity with which are the epithelial cells of the biliary ducts, to which , at the lower part of the figures, the much larger hepatic cells suddenly succeed.

Hepatic Cells and Bile Capilaries

Hepatic cells and bile capillaries, from the liver of a child three months old. Both figures represent…

Section through anterior corpus quadrigeminum and part of optic thalamus. Labels: s, aqueduct of Sylvius; gr. gray matter of aqueduct; c.q.s., quadrigeminal eminence; l., stratum lemnisci; o, stratum opticum; c., stratum cinereum; Th., pulvinate of optic thalamus; c.q.e., c.g.i., lateral and median corpora geniculata; br.s., br.i., superior and inferior brachia; f., fillet; p.l., posterior longitudinal bundle; r., raphe; III., third nerve, and n.III., its nucleus; l.p.p., posterior perforated space; s.n., substantia nigra, above this is the tegmentum with the circular area of the red nucleus; cr., crusta; II., optic tract; M., medullary center of hemisphere; n.c., nucleus caudatus; st., stria terminalis.

Corpus Quadrigeminum

Section through anterior corpus quadrigeminum and part of optic thalamus. Labels: s, aqueduct of Sylvius;…

Section through the eye carried through the ciliary processes. Labels: 1, Cornea; 2, membrane of Descemet; 3, sclerotic; 3', cornea-scleral junction; 4, canal of Schlemm; 5, vein; 6, nucleated network on inner wall of canal Schlemm; 7, lig. pectinatum iridis, abc; 8, iris stroma; 9, pigment of iris; 10, ciliary processes; 11, ciliary muscles; 12, choroid tissue; 13, meridional and 14, radiating fibers of ciliary muscle; 15, ring-muscle of Muller; 16, circular or angular bundles of ciliary muscle.

Ciliary Processes of the Eye

Section through the eye carried through the ciliary processes. Labels: 1, Cornea; 2, membrane of Descemet;…

"The Watered Pecten belongs to the scallop-shells. The shell is generally nearly circular, more or less elongated, and terminated toward the summit in a straight line."

Pecten Pseudamussium (Chenu.)

"The Watered Pecten belongs to the scallop-shells. The shell is generally nearly circular, more or less…

"Section through right ear. 1, helix; 2, concha; 3, outer passage; 4, 5, 6, semi-circular canals; 7, oval window; 8, cochlea; 9, Eustachian tube; 10, eardrum." -Foster, 1921

Ear

"Section through right ear. 1, helix; 2, concha; 3, outer passage; 4, 5, 6, semi-circular canals; 7,…

Stomach turned inside out, showing dissection of oblique and circular muscular coats.

Stomach Turned Inside Out

Stomach turned inside out, showing dissection of oblique and circular muscular coats.

A wheel is a circular device that is capable of rotating on its axis, facilitating movement or transportation.

Wheel

A wheel is a circular device that is capable of rotating on its axis, facilitating movement or transportation.

A cast net, also called a throw net, is a net used for fishing. It is a circular net with small weights distributed around its edge.

Cast Net

A cast net, also called a throw net, is a net used for fishing. It is a circular net with small weights…

"Decorticator for ramie, jute, hemp, flax, and other textiles in green stalks. The machine is quadruple in its action. It consists in four feeders and four cleaners, inside of which revolves, horizontally, a large cogged wheel acting as a circular carrier. It brings the crushed plant in, and draws from it, the revolving cleaners, as follows: A, crushing rollers, through which the green stalks are passed, and placed on the rim of the large cogged wheel or circular carrier. B,rim of the carrier, on which hangs the flattened plant coming from the rollers. C, revolving cleaners, furnished with knives attracting the plant while it is drawn by the circular motion of the carrier. D, small cog-wheels in contact with the large wheels, and keeping the plant under pressure. F, projecting bar to direct the fiber into the cleaners. G, opening to take off the cleaned fiber." -Watts, 1874

Decorticator

"Decorticator for ramie, jute, hemp, flax, and other textiles in green stalks. The machine is quadruple…

Stonehenge is a prehistoric monument located in the English county of Wiltshire, about 3.2 kilometres (2.0 mi) west of Amesbury and 13 kilometres (8.1 mi) north of Salisbury. One of the most famous prehistoric sites in the world, Stonehenge is composed of earthworks surrounding a circular setting of large standing stones.

Ruins at Stonehenge

Stonehenge is a prehistoric monument located in the English county of Wiltshire, about 3.2 kilometres…

The figure on the left shows fibers of the external longitudinal layer. The middle figure shows fibers of the middle circular layer. The figure on the right shows the fibers of the internal longitudinal layer.

Fibers of the Bladder

The figure on the left shows fibers of the external longitudinal layer. The middle figure shows fibers…

The Confederate rosette and badge was worn by supporters of the Southern Confederation.

Confederate Rosette and Badge

The Confederate rosette and badge was worn by supporters of the Southern Confederation.

Throughout the dorsal region, the spinal cord presents a uniform girth and a very nearly circular outline when seen in transverse section. Shown is the roots and origin of the seventh dorsal nerve.

Seventh Dorsal Nerve

Throughout the dorsal region, the spinal cord presents a uniform girth and a very nearly circular outline…

An illustration of Castle Garden, known today as Castle Clinton or Fort Clinton. Castle Clinton or Fort Clinton was once a circular sandstone fort now located in Battery Park at the southern tip of Manhattan, New York City, in the United States. It subsequently became a beer garden, a theater, the first immigration station (predating Ellis Island), a very popular public aquarium, and finally a national monument.

Castle Garden

An illustration of Castle Garden, known today as Castle Clinton or Fort Clinton. Castle Clinton or Fort…

An illustration of the interior of Castle Garden, known today as Castle Clinton or Fort Clinton. Castle Clinton or Fort Clinton was once a circular sandstone fort now located in Battery Park at the southern tip of Manhattan, New York City, in the United States. It subsequently became a beer garden, a theater, the first immigration station (predating Ellis Island), a very popular public aquarium, and finally a national monument.

Castle Garden (Interior)

An illustration of the interior of Castle Garden, known today as Castle Clinton or Fort Clinton. Castle…

With the plane, one can make rough wood true, smooth and beautiful. The name plane, perhaps, comes from the work it does, for it is used to smooth or reduce wood to a true plane.

Circular Plane

With the plane, one can make rough wood true, smooth and beautiful. The name plane, perhaps, comes from…

The three layers of the muscular coat of the stomach. A, Outer or longitudinal layer. B, Middle or circular layer. C, Internal or oblique layer. Labels: a, longitudinal fibers of esophagus; b, superficial circular fibers of esophagus passing into circular fibers of stomach in B; c, deep circular fibers of esophagus passing into oblique fibers of stomach in C; d, oblique fibers forming rings at the fundus; e, submucosa.

Stomach Muscles

The three layers of the muscular coat of the stomach. A, Outer or longitudinal layer. B, Middle or circular…

Diagram to show formation of pylorus. Labels: P, peritoneum; L, longitudinal layer of muscular fibers; C, circular layer; M, mucous membrane; V, villi. It will be seen that the pyloric narrowing is due practically entirely to a gradual thickening of the circular muscular fibers, which stops abruptly at the pyloric orifice.

Formation of Pylorus

Diagram to show formation of pylorus. Labels: P, peritoneum; L, longitudinal layer of muscular fibers;…

A decorative Egyptian pillar. A pillar is similar to a column which is a vertical support structure in architecture, but the base section is any shape but circular.

Pillar

A decorative Egyptian pillar. A pillar is similar to a column which is a vertical support structure…

The purely conventional ornaments — the rosette, guilloche, and lotus-flower, and probably also the palmette — were derived from Egyptian originals. They were treated, however, in a quite new spirit and adapted to the special materials and uses of their environment. Thes the form of the palmette, even if derived, as is not likely, from the Egyptian lotus-motive, was assimilated to the more familiar palm-forms of Assyria.

Assyrian Ornament

The purely conventional ornaments — the rosette, guilloche, and lotus-flower, and probably also…

A barrel vault, also known as a tunnel vault or a wagon vault, is an architectural element formed by the extrusion of a single curve (or pair of curves, in the case of a pointed barrel vault) along a given distance. The curves are typically circular in shape, lending a semi-cylindrical appearance to the total design. The barrel vault is the simplest form of a vault: effectively a series of arches placed side by side, i.e., one after another.

Barrel Vault

A barrel vault, also known as a tunnel vault or a wagon vault, is an architectural element formed by…

The circular so-called "Temple of Vesta" at Tivoli, of the early first century BCE, has been widely admired since the Renaissance. Its ruins sit on the acropolis of the Etruscan and Roman city of Tibur (now Tivoli), overlooking the falls of the Aniene in a picturesque narrow gully.

Temple of Vesta, Tivoli

The circular so-called "Temple of Vesta" at Tivoli, of the early first century BCE, has been widely…

An illustration depicting the formation of circles of diffusion. "From point A luminous rays enter the eye in the form of a cone, the kind of which will depend on the pupil. Thus it may be circular, or oval, or ever triangular. If the pencil is focused in front of the retina, as at d, or behind it as it as at f, or, in other words, if the retina of being at F; be in the position G or H, there will be a luminous circle or a luminous triangular space, and many elements of the retina will be affected. The size of these diffusion circles depends on the distance from the retina of the point where the rays are focused: the greater the distance, the more extended will be the diffusion circle" (Britannica, 132).

Formation of Circles of Diffusion

An illustration depicting the formation of circles of diffusion. "From point A luminous rays enter the…

"This turbine was designed to give 1250 H.P. with a fall of 25 ft. and an efficiency of 77%. It is fitted with a suction pope and a circular balanced sluice for admitting and cutting off the water-siupply" (Britannica, 384).

Jonval Turbine

"This turbine was designed to give 1250 H.P. with a fall of 25 ft. and an efficiency of 77%. It is fitted…

Circular and polygonal plans appear in a number of Syrian examples of the early sixth century. Their most striking feature is the inscribing of the circle of polygon in a square which forms the exterior outline, and the use of four niches to fill out the corners. This occurs at Kelat Seman, a small double church, perhaps the tomb and chapel of a martyr; in the cathedral at Bozrah, and in the small domical church of St. George at Ezra. These were probably the prototypes of many Byzantine churches like St. Sergius at Constantinople, and San Vitale at Ravenna.

Cathedral at Bosra

Circular and polygonal plans appear in a number of Syrian examples of the early sixth century. Their…

A pendentive is a constructive device permitting the placing of a circular dome over a square room or an elliptical dome over a rectangular room. The pendentives, which are triangular segments of a sphere, taper to points at the bottom and spread at the top to establish the continuous circular or elliptical base needed for the dome. In masonry the pendentives thus receive the weight of the dome, concentrating it at the four corners where it can be received by the piers beneath.

Diagram of Pendentives

A pendentive is a constructive device permitting the placing of a circular dome over a square room or…

An illustration of circular plaque decorated with a rosette.

Decorative Plaque

An illustration of circular plaque decorated with a rosette.

An earring with of circular open work set with small diamonds.

Earring

An earring with of circular open work set with small diamonds.

A: Penetrations by small semi-circular vaults sprung from same level. B: Intersection by small semicircular vault sprung from higher level; groins form wavy line. C: Intersection by narrow pointed vault sprung from same level; groins are plane curves.

Vaults, Penetrations and Intersections

A: Penetrations by small semi-circular vaults sprung from same level. B: Intersection by small semicircular…

A Rose window (or Catherine window) is often used as a generic term applied to a circular window, but is especially used for those found in churches of the Gothic architectural style and being divided into segments by stone mullions and tracery. The name "rose window" was not used before the 17th century and according to the Oxford English Dictionary, among other authorities, comes from the English flower name rose.

Rose Window, Church of St. Ouen, Rouen

A Rose window (or Catherine window) is often used as a generic term applied to a circular window, but…

The same gothic principles controlled the designing of houses, farm buildings, barns, granaries, and the like. The finest palaces are well represented by the Ducal Palace at Nancy (1476), the Hotel de Cluny at Paris (1485), and the Hotel Jacques at Bourges. These palaces are elaborately planned, with large halls, many staircases, and handsome courts; they are also extremely picturesque with their square and circular towers, slender turrets, elaborate dormers, and rich carved detail.

Hotel Jacques Coeur, Bourges

The same gothic principles controlled the designing of houses, farm buildings, barns, granaries, and…

"Industrial-railway Turn-table. a, circular base with channel for ball-bearing, showing ring of balls; b, under side of table; c, table in position, showing cross-tracks; d, latch for cover. A car is run by hand on the turn-table, the table turned one quarter of the way round, and the car run off on a track at right angles to the first track." -Whitney, 1911

Railway Turntable

"Industrial-railway Turn-table. a, circular base with channel for ball-bearing, showing ring of balls;…

A pillar is similar to a column which is a vertical support structure in architecture, but the base section is any shape but circular. Tschultri, or choultry, is a resting place for visitors where rooms and food are provided by a charitable institution for nominal rates. Some were guest-houses where accommodation is free of charge. Choultries were famous in Colonial India. It was an Hindu-Caravanserai or a Colonnade. It was a typical ancient Indian type of hotel.

Pillar in Trimal Naik's Tschultri

A pillar is similar to a column which is a vertical support structure in architecture, but the base…

"In geometry, certain transcendental curves having, in polar coordinates, equations of the form ρ = a cos b θ. A, three-leaved rose of equation ρ = a sin 3 θ." -Whitney, 1911

Rose

"In geometry, certain transcendental curves having, in polar coordinates, equations of the form ρ…

"In geometry, certain transcendental curves having, in polar coordinates, equations of the form ρ = a cos b &theta. B, three-leaved rose of equation ρ = a cos 3 &theta." -Whitney, 1911

Rose

"In geometry, certain transcendental curves having, in polar coordinates, equations of the form ρ…

"In geometry, certain transcendental curves having, in polar coordinates, equations of the form ρ = a cos b &theta. C, four-leaved rose of equation ρ = a sin 2 &theta." -Whitney, 1911

Rose

"In geometry, certain transcendental curves having, in polar coordinates, equations of the form ρ…

"In geometry, certain transcendental curves having, in polar coordinates, equations of the form ρ = a cos b &theta. D, four-leaved rose of equation ρ = a cos 2 &theta." -Whitney, 1911

Rose

"In geometry, certain transcendental curves having, in polar coordinates, equations of the form ρ…

In some temples the pillars have, in lieu of capital, the face of a goddess, probably of Isis, with a drooping sacerdotal hood, and supporting a temple on the head. This face is repeated on four sides of the circular shaft.

Capital in the Temple at Denderah

In some temples the pillars have, in lieu of capital, the face of a goddess, probably of Isis, with…

The columns in the ruins of Persepolis are circular and slender, and have capitals and bases. The capital generally consists of two half-horses or bulls, whose fore feet overlap the border of the shaft, and which are placed back to back.

Capital and Entablature from the Rock Tomb of Darius

The columns in the ruins of Persepolis are circular and slender, and have capitals and bases. The capital…

Other capitals are more compact, where from the lower part, which is in the shape of a globular vessel, rises a slender cup, supporting a lofty member with double volutes or scrolls on the four sides, which correspond with those of the Grecian Ionic capitals, but which are introduced not horizontally but perpendicularly. The base consists of fillets and a leaf-covered torus resting on a circular path.

Restored Capital from the Ruins of Persepolis

Other capitals are more compact, where from the lower part, which is in the shape of a globular vessel,…

Other capitals are more compact, where from the lower part, which is in the shape of a globular vessel, rises a slender cup, supporting a lofty member with double volutes or scrolls on the four sides, which correspond with those of the Grecian Ionic capitals, but which are introduced not horizontally but perpendicularly. The base consists of fillets and a leaf-covered torus resting on a circular path.

Capital from the Ruins of Persepolis

Other capitals are more compact, where from the lower part, which is in the shape of a globular vessel,…

Other capitals are more compact, where from the lower part, which is in the shape of a globular vessel, rises a slender cup, supporting a lofty member with double volutes or scrolls on the four sides, which correspond with those of the Grecian Ionic capitals, but which are introduced not horizontally but perpendicularly. The base consists of fillets and a leaf-covered torus resting on a circular path.

Volute of the Persian Column

Other capitals are more compact, where from the lower part, which is in the shape of a globular vessel,…

Remains of the circular walls round towns and palaces, which are known under the name Cyclopean, exist at the present day. These are found both in Greece itself and in many of the Greek colonies, as in Italy and Sardinia. Such walls consist of gigantic polygonal blocks of stone, the corners of which fit accurately into one another. Other structures of this kind consist of regular blocks of equal height. Both kinds are constructed entirely without mortar.

Cyclopean Masonry

Remains of the circular walls round towns and palaces, which are known under the name Cyclopean, exist…

Remains of the circular walls round towns and palaces, which are known under the name Cyclopean, exist at the present day. These are found both in Greece itself and in many of the Greek colonies, as in Italy and Sardinia. Such walls consist of gigantic polygonal blocks of stone, the corners of which fit accurately into one another. Other structures of this kind consist of regular blocks of equal height. Both kinds are constructed entirely without mortar. The Lion Gate served as the gateway to the city of Mycenæ.

The Lion Gate at Mycenæ

Remains of the circular walls round towns and palaces, which are known under the name Cyclopean, exist…