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A man sitting at a desk, with a boy standing in front, with his eyes closed.

Man at desk and boy

A man sitting at a desk, with a boy standing in front, with his eyes closed.

"There are three pairs of salivary glands. One pair lies under the tongue; one pair is found under the corners of the lower jaw; and the other pair is found in front of and below the ears." — Ritchie, 1918

Salivary glands

"There are three pairs of salivary glands. One pair lies under the tongue; one pair is found under the…

The front of a roman coin.

Roman Coin

The front of a roman coin.

A graduated cylinder.

Graduated cylinder

A graduated cylinder.

Three cylindrical weights, suspended on ropes and pulleys.

Weights and Pulleys

Three cylindrical weights, suspended on ropes and pulleys.

"The wheel and axle consists of a wheel united to a cylinder in such a way that they may turn together on a common axis. It is a modified lever of the first or second class." — Avery, 1895

Wheel and axle

"The wheel and axle consists of a wheel united to a cylinder in such a way that they may turn together…

"That the screw is a modified inclined plane, may be shown by winding a triangular piece of paper around a cylinder." — Avery, 1895

Diagram of a screw

"That the screw is a modified inclined plane, may be shown by winding a triangular piece of paper around…

"The lift pump or suction-pump consists of a cylinder or barrel, piston, two valves, and a suction pipe, the lower end of which dips below the surface of the liquid to be raised." — Avery, 1895

Lift pump

"The lift pump or suction-pump consists of a cylinder or barrel, piston, two valves, and a suction pipe,…

"The operation of the force-pump is similar to that of the suction-pump. The outlet-valve generally opens from the cylinder, the piston being made solid." — Avery, 1895

Force pump

"The operation of the force-pump is similar to that of the suction-pump. The outlet-valve generally…

"Place a bit of tinder in the cavity of the piston of the 'fire-syringe'. Put the piston into the open end of the cylinder and force it in, compressing the confined air as abruptly as possible. Promptly remove the piston. The tinder will probably be on fire." — Avery, 1895

Fire syringe

"Place a bit of tinder in the cavity of the piston of the 'fire-syringe'. Put the piston into the open…

"Consists of a coil of wire wound in two broad grooves plowed on opposite sides of an iron cylinder." — Avery, 1895

Siemens armature

"Consists of a coil of wire wound in two broad grooves plowed on opposite sides of an iron cylinder."…

"The drum armature differs from the shuttle armature chiefly in that it employs many coils instead of one. The cylindrical iron core is made of thin disks of soft iron in insulated from each other, thus minimizing the 'local currents' and the heating effects thereof." — Avery, 1895

Drum armature

"The drum armature differs from the shuttle armature chiefly in that it employs many coils instead of…

"Orthorhombic. Crystals resemble closely those of barite. Commonly tabular parallel to the base or prismatic parallel to the brachy- or macro-axis with prominent development of the domes. Crystals which are elongated parallel to the brachy-axis are frequently terminated in front by four faces in nearly equal development, consisting of 2 prism faces and 2 of the macrodome." — Ford, 1912

Celestite

"Orthorhombic. Crystals resemble closely those of barite. Commonly tabular parallel to the base or prismatic…

"View of Siege Works." — Greenough, 1899

Siege Works

"View of Siege Works." — Greenough, 1899

"Side view of built up armature core. The sheet metal ring sections containing the teeth are fastened into dovetail notches in the spider as shown." — Hawkins, 1917

Armature core

"Side view of built up armature core. The sheet metal ring sections containing the teeth are fastened…

The front of a copeck of emperor Nicholas.

Copeck

The front of a copeck of emperor Nicholas.

The front of a copeck of emperor Nicholas.

Copeck

The front of a copeck of emperor Nicholas.

A man's cub. "Look!" said Father wolf. In front of him stood a naked baby, who could just walk.

Mowgli's Brothers

A man's cub. "Look!" said Father wolf. In front of him stood a naked baby, who could just walk.

"The Umbrella Bird is a native of Peru. It is about the size of a crow, with deep black plumage; the head is adorned with a large spreading crest, which arises from a contractile skin, and capable of being erected at will; the shafts of the crest-feathers are white, and the plumes glossy blue, hair-like and curved outward at the tips. When the crest is laid back the shafts form a compact white mass, sloping up from the back of the head; when it is erected the shafts radiate on all sides from the top of the head, reaching in front beyond and below the beak, which is thus completely concealed from view. A long cylindrical plume hangs down from the middle of the neck; the feathers of the plume lap over each other like scales, and are bordered with metallic blue. Umbrella birds associate in small flocks, and live almost entirely upon fruits. Their cry, which resembles the lowing of a cow, is most frequently heard just before sunrise and after sunset."—(Charles Leonard-Stuart, 1911)

Umbrellabird

"The Umbrella Bird is a native of Peru. It is about the size of a crow, with deep black plumage; the…

Bronze door of the Capitol, Eastern front entrance.

Capitol Door

Bronze door of the Capitol, Eastern front entrance.

View of Oil City in Pennsylvania.

Oil City

View of Oil City in Pennsylvania.

Architecture of Cathredals in England. Perpendicular window, West Front at Norwich Cathedral, inserted in a Norman wall.

Window

Architecture of Cathredals in England. Perpendicular window, West Front at Norwich Cathedral, inserted…

Nicholson's Hydrometer, consists of a hollow cylinder of metal with conical ends, terminated above by a very thin rod bearing a small dish, and carrying at its lower end a kind of basket. This latter is of such weight that when the instrument is immersed in water a weight of 100 grammes must be placed in the dish above in order to sink the apparatus as far as a certain mark on the rod. By the principle of Archimedes, the weight of the instrument, together with the 100 grammes which it carries, is equal to the weight of the water displaced. Now, let the instrument be placed in another liquid, and the weights in the dish above be altered until they are just sufficient to make the instrument be placed in another liquid, and the weights in the dish above be altered until they are just sufficient to make the instrument sink to the mark on the rod.

Hydrometer

Nicholson's Hydrometer, consists of a hollow cylinder of metal with conical ends, terminated above by…

Nicholson's Hydrometer, consists of a hollow cylinder of metal with conical ends, terminated above by a very thin rod bearing a small dish, and carrying at its lower end a kind of basket. This latter is of such weight that when the instrument is immersed in water a weight of 100 grammes must be placed in the dish above in order to sink the apparatus as far as a certain mark on the rod. By the principle of Archimedes, the weight of the instrument, together with the 100 grammes which it carries, is equal to the weight of the water displaced. Now, let the instrument be placed in another liquid, and the weights in the dish above be altered until they are just sufficient to make the instrument be placed in another liquid, and the weights in the dish above be altered until they are just sufficient to make the instrument sink to the mark on the rod.

Hydrometer

Nicholson's Hydrometer, consists of a hollow cylinder of metal with conical ends, terminated above by…

This air pump contains a glass or metal cylinder called the barrel, in which a piston works. The piston has an opening through it which is closed at the lower end by a valve S opening upwards. The barrel communicates with a passage leading to the centre of a brass surface

Air Pump

This air pump contains a glass or metal cylinder called the barrel, in which a piston works. The piston…

"Organs in the body cavity viewed from the front." —Davison, 1910

Organs of the Body Cavity

"Organs in the body cavity viewed from the front." —Davison, 1910

"Muscles on the front of the arm. Note the while cords, the tendons at the wrist." —Davison, 1910

Muscles of the Arm

"Muscles on the front of the arm. Note the while cords, the tendons at the wrist." —Davison, 1910

"Part of the nervous system viewed in front." —Davison, 1910

Nervous System

"Part of the nervous system viewed in front." —Davison, 1910

"Part of the sympathetic nervous system seen from in front, n, one of the two chief cords, t, i, and p, branches to organs." —Davison, 1910

Sympathetic Nervous System

"Part of the sympathetic nervous system seen from in front, n, one of the two chief cords, t, i, and…

"A modern small house with the 'lean-to' motif. Notice that the long slope faces the front." —Kinne, 1920

Modern house

"A modern small house with the 'lean-to' motif. Notice that the long slope faces the front." —Kinne,…

"The lacteals conduct the chyle from the intestines into numerous glands nearby, called the mesenteries, from which a fewer number of lacteals lead the chyle into one large tube in front of the spinal column, called the thoracic duct." —Brown, 1884

Thoracic duct and lacteals

"The lacteals conduct the chyle from the intestines into numerous glands nearby, called the mesenteries,…

Part of the nervous system viewed from in front.

Nervous System

Part of the nervous system viewed from in front.

A side view of the two great cavities of the body and their organs. 1: The mouth. 2: The thorax. 3: The abdomen. 4: The brain. 5: The spinal cord. 6: A salivary gland. 7: The aesophagus. 8: The trachea and lungs. 9: The heart. 10: The liver. 11: The stomach. 12: The colon. 13: The small intestine. 14: The lacteals. 15: The thoracic duct. 16: The diaphragm. 17, 18, and 20: The walls of the lower cavity, composed of bones, muscles and skin. 19 and 20: The walls of the upper cavity.

Side View of the Body

A side view of the two great cavities of the body and their organs. 1: The mouth. 2: The thorax. 3:…

The position of the organs of the mouth, thorax, and abdomen. 1, 2, and 3: Salivary glands. 4: The larynx and trachea. 5: The aesophagus. 6: The lungs. 7: The heart. 8: The liver. 9: The stomach. 10: The pancreas. 11: The spleen. 13: The small intestine. 14: The large intestine.

Front View of the Body

The position of the organs of the mouth, thorax, and abdomen. 1, 2, and 3: Salivary glands. 4: The larynx…

The right knee-joint, laid open from the front. 1: Articular surface of the femur. 2 and 3: Ligaments. 4: Insertion of one of these ligaments into the tibia. 6 and 7: Internal and external cartilages. 8: Ligament of the patella.

Knee-Joint

The right knee-joint, laid open from the front. 1: Articular surface of the femur. 2 and 3: Ligaments.…

Front view of the right knee-joint. 1: Tendon of the extensor muscle. 2: Patella. 3: Ligament of the patella, or trendinous insertion of the muscle just mentioned. 4: Capsular ligament. 5 and 6: Internal and external lateral ligaments.

Knee-Joint

Front view of the right knee-joint. 1: Tendon of the extensor muscle. 2: Patella. 3: Ligament of the…

A side view of face. 1 and 2: Trachea. 3: Esophagus. 4, 5, and 6: Muscles. 7: Submaxillary. 8: Parotid gland. 9: Duct from the Parotid gland.

Face

A side view of face. 1 and 2: Trachea. 3: Esophagus. 4, 5, and 6: Muscles. 7: Submaxillary. 8: Parotid…

The teeth of a carnivorous animal that lives on flesh alone. The front teeth are tearing ones, while the back teeth have sharp edges for cutting. The flesh is first torn by the front teeth, and then it is cut up by the back ones.

Carnivorous Skeleton

The teeth of a carnivorous animal that lives on flesh alone. The front teeth are tearing ones, while…

Diagramatic view of the convulate vernated leaf.

Convulate

Diagramatic view of the convulate vernated leaf.

A firearm resembling a pistol, but differing from it in having a breech-loading cylinder so arranged that the cocking of the hammer revolves it and brings the next cartridge in line for firing.

Revolver

A firearm resembling a pistol, but differing from it in having a breech-loading cylinder so arranged…

"A prophetic birds eye view of Ruhleben Prison Camp when the war ends."-1916; Drawing by Hobart Egremont, one of the interned.

Ruhleben Prison Camp

"A prophetic birds eye view of Ruhleben Prison Camp when the war ends."-1916; Drawing by Hobart Egremont,…

The front of an English crown coin.

Crown Coin

The front of an English crown coin.

A money or coin in Portugal. Front.

Crusado

A money or coin in Portugal. Front.

A powerful carnivorous mammal of the cat family. The adult is about eight feet long and three to four feet high. Its front feet have five toes and the hinder feet four, and all the characterized by strong retractile claws.

Tiger

A powerful carnivorous mammal of the cat family. The adult is about eight feet long and three to four…

This illustration shows the proportions of volume in which hydrogen and oxygen combine by introducing the two gases into a tube, filled with mercury and inverted within a cylinder of mercury.

Mercury Tube

This illustration shows the proportions of volume in which hydrogen and oxygen combine by introducing…

This illustration shows the shortened types of stems: A, corm of jack-in-the-pulpit. At left surface view showing lateral buds, roots and sheathing leaf arising from top of shortened stem. At right sectional view with folded leaf, l, in bud at apex stem. B, bulb type of shortened stems. At left bulb of onion showing the ensheathing leaves which are swollen at their bases with food, thus forming the bulb. At right, section of a bulb of hyacinth showing the fleshy leaves attached to the very short stem and in the center of the bulb a flower cluster.

Onion

This illustration shows the shortened types of stems: A, corm of jack-in-the-pulpit. At left surface…

This illustration shows the colonial forms of unicellular green algae: A, Pediastrum, the plants of the colony being arranged in a flat plate. B, a view of the outer cells of the colony showing the formation of a new colony. C, one of these new colonies. D, a plant of the water net containing a young colony. E, enlarged view of one of the meshes of a net showing the geometrical arrangement of the plants.

Green Algae

This illustration shows the colonial forms of unicellular green algae: A, Pediastrum, the plants of…

This illustration shows further development of the ascocarp: A, sectional view, showing the branches, s, derived from the germinating gametospore, that are forming numerous lateral branchlets. B, one of the branchlets enlarged, showing how it divides into cells which round off, forming the asci, as. C, ascospore. D, germinating ascspore.

Ascocarp

This illustration shows further development of the ascocarp: A, sectional view, showing the branches,…

This illustration shows an enlarged view of the mycelium, ascocarp, etc., of one of the mildews, Erysiphe: c, erect hyphae forming spores or conidia; h, haustoria penetrating epidermis of leaf; a, ascocarp or perithecium.

Mycelium

This illustration shows an enlarged view of the mycelium, ascocarp, etc., of one of the mildews, Erysiphe:…

This illustration shows the germination of the gametospore: A, section of a mature archegonium with canal cells dissolved, thus forming a passageway to the large female gamete, g. B, sectional view of base of archegonium, showing the germinating gametospore in two-cell stage. The perianth, p, is seen growing up about the archegonium. C, later stage in growth of the gametospore. The lower cell shown in B is forming stalk cells, while the outer cell has produced densely granular cells that will later by further division form spore mother cells and elaters.

Gametospore

This illustration shows the germination of the gametospore: A, section of a mature archegonium with…

This illustration shows the structure of capsule of Funaria: 5, capsule with calyptra, 5A, removed. 6, section of nearly mature capsule-sp, spore-forming cells surrounded on outside by loosely arranged chlorophyll-bearing cells; o, operculum; r, annulus; p, peristome; a, apophysis. 8, magnified view of a portion of the capsule, showing the annulus, r, and the thick-walled cells of the peristome, p, which are attached at their base to the epidermis by a double row of cells; sp, spore-forming cells, the doted line should run to the four roundish cells at the left. 7, the cells shown in 8, p, have split apart, thus orming the inner and outer teeth-like segments of the peristome.

Funaria

This illustration shows the structure of capsule of Funaria: 5, capsule with calyptra, 5A, removed.…

This illustration shows stages in the germination of the gametospore of Lepidium, sectional view: A, micropylar end of embryo sac, showing the enlarging gametospore provided with cell wall and attached to wall of sac. B, later growth-s, suspensor; e, embryo cell; en, endosperm cells. C, pro-embryo after first division of embryo cell. D, further divisions of embryo cell, showing formation of an epidermis and a central stem region. E, later growth, two growing regions, the cotyledons, appearing on the sides of the stem. F, plant or embryo, consisting of two cotyledons, c; stem, st, which terminates in the root, r; the endosperm cells, en, are ebing absorbed by the enlarging embryo; s, suspensor.

Lepidium

This illustration shows stages in the germination of the gametospore of Lepidium, sectional view: A,…

This illustration shows the skull of a tapir. Tapirs are large browsing animals, roughly pig-like in shape but with short, prehensile trunks and large front overbites.

Tapir Skull

This illustration shows the skull of a tapir. Tapirs are large browsing animals, roughly pig-like in…

This diagram shows some stages in the life history of the tapeworm. A, Cysticercus or Bladderworm stage, before the "head" protrudes from the bladder; B, same, later stage; C, Strobila, or chain of proglottides, many being omitted; D, embryo such as fill the uterus of the mature proglottides. It is protected by a shell. b, bladder; ex., excretory canals; g, genital pore; h, head or scolex provided with hooks and suckers (s); u, uterus in a mature posterior proglottis; z, one of budding or segment formation. The numerals show the approximate number of segments, reckoning from the front.

Tapeworm

This diagram shows some stages in the life history of the tapeworm. A, Cysticercus or Bladderworm stage,…

This diagram shows a fresh-water annelid. a, appendages; br., brain; d, dissepiments; i, intestine; m, mouth; nph, nephridium; oe, aesophagus; p, pavilion, line with ciliated entoderm; ph., pharynx; pr., processes from the anal segment; z, zone immediately in front of the anal segment where new segments are continually being formed; z', the zone of fission or budding. This takes place in the middle of a segment. The anterior half-segment of z' will produce a region like z for the anterior half of the worm.

Annelid

This diagram shows a fresh-water annelid. a, appendages; br., brain; d, dissepiments; i, intestine;…

Diagram of the mouth of a snail, showing the lingual ribbon. br, brain; c, buccal cavity; co., caelom; g, gullet; j, jaw, against which the radula works; m, mouth; r., radula; r.s., radula sac, in which the radula is renewed as it is worn away in front.

Snail

Diagram of the mouth of a snail, showing the lingual ribbon. br, brain; c, buccal cavity; co., caelom;…

This diagram shows a side view of the right eye of man. a.c., central artery; a.h., aqueous humor; b., blind spot, the entrance of the optic nerve; c, conjunctiva; ch., choroid layer of the eye-ball; c.l., crystalline lens; c.m.c., circular fibers of the ciliary muscles; c.m.r., radial fibers of the ciliary muscles; co., cornea, the transparent portion of the sclerotic; c.p., ciliary process; c.s., canal of Schlemm, a lymphatic vessel; fo., fovea centralis, the point of clearest vision; o.n., optic nerve; o.s., ora serrata, the anterior wavy margin of the visual portion of the retina; r, the retinal layer; sc., sclerotic layer; sh., sheath of theoptic nerve; v.h., vitreous humor.

Human Eye

This diagram shows a side view of the right eye of man. a.c., central artery; a.h., aqueous humor; b.,…

a solid which may be concieved as generated by the revolution of a rectangle about one of its sides.

Right Cylinder

a solid which may be concieved as generated by the revolution of a rectangle about one of its sides.

This illustration shows the skull of a rattlesnake. ar, articular portion of lower jaw; de, dentary portion; bo, basi-occipatal; mx, maxilla, bearing poison fang; na, nasal; pl, palatine, the front end being represented by a dotted line as though seen through the maxilla; pmx, premaxilla; po, post frontal; pr, prefrontal; pt, pterygoid; qu, quadrate; sq, squamosal; tr, transverse bone.

Rattlesnake Skull

This illustration shows the skull of a rattlesnake. ar, articular portion of lower jaw; de, dentary…

A stringed instrument used in Carnatic music. The vina is played by sitting cross-legged and holding the vina in front of oneself. The small gourd on the left rests on the left thigh, the left arm passing beneath and hand curved round the stem so that the fingers rest upon the frets. The vina's main body is placed on the ground, partially supported by the right thigh.

Vina

A stringed instrument used in Carnatic music. The vina is played by sitting cross-legged and holding…