"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius of curvature of the inner face of an annular lens. The outer face is the same as that of an ordinary annular lens, which the other face, though straight in the vertical, is ground to the required curve in the horizontal plane. The rays f'fc falling upon the lens x converge to the vertical focal plane ff and afterwards diverge through the smaller horizontal angle x'f'x', and so for any other case." —The Encyclopedia Britannica, 1910

Differential Lens

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the…

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius of curvature of the inner face of an annular lens. The outer face is the same as that of an ordinary annular lens, which the other face, though straight in the vertical, is ground to the required curve in the horizontal plane. The rays f'fc falling upon the lens x converge to the vertical focal plane ff and afterwards diverge through the smaller horizontal angle x'f'x', and so for any other case." —The Encyclopedia Britannica, 1910

Differential Lens

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the…

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius of curvature of the inner face of an annular lens. The outer face is the same as that of an ordinary annular lens, which the other face, though straight in the vertical, is ground to the required curve in the horizontal plane. The rays f'fc falling upon the lens x converge to the vertical focal plane ff and afterwards diverge through the smaller horizontal angle x'f'x', and so for any other case." —The Encyclopedia Britannica, 1910

Differential Lens

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the…

This is an early 20th century hat display. It includes three hats, a long shawl, purse, and hat pins on a cushion. The hats have a netting material in the front for covering the face.

Hat Display

This is an early 20th century hat display. It includes three hats, a long shawl, purse, and hat pins…

A dissection of the head, face, and neck.

Dissection

A dissection of the head, face, and neck.

A divider with a face in the center.

Divider

A divider with a face in the center.

Edison talking into the phonograph.

Thomas Edison

Edison talking into the phonograph.

Edison talking into the phonograph.

Thomas Edison

Edison talking into the phonograph.

"In architecture, a sculptured ornament in imitation of a garland or festoon of fruits, leaves, or flowers, or of other objects, suspended between two points." -Whitney, 1911

Encarpus

"In architecture, a sculptured ornament in imitation of a garland or festoon of fruits, leaves, or flowers,…

Ethmoid bone from above.

Ethmoid Bone from Above

Ethmoid bone from above.

Ethmoid bone from behind.

Ethmoid Bone from Behind

Ethmoid bone from behind.

The outer surface of the ethmoid bone.

Outer Surface of Ethmoid Bone

The outer surface of the ethmoid bone.

Perpendicular plate of ethmoid, shown by removing the right lateral mass.

Perpendicular Plate of Ethmoid

Perpendicular plate of ethmoid, shown by removing the right lateral mass.

"The Relative Position of the Lachrymal Apparatus, the Eyeball, and the Eyelids. <I>A</em>, lachrymal canals, with the minute orifices represented as two black dots to the right; <em>B</em>, tendon attached to a muscle which surrounds the circumference of the orbit and eyelids; under <em>B</em> is seen the lachrymal sac. The minute openings of the Meibomian glands are seen on the free margins of the eyelids. Below <em>A</em> is seen a small conical elevation, with black dots (the lachrymal papilla, or caruncle)." &mdash; Blaisedell, 1904

Eyeball

"The Relative Position of the Lachrymal Apparatus, the Eyeball, and the Eyelids. A, lachrymal canals,…

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…

A face turned to the side.

Face

A face turned to the side.

A face turned up.

Face

A face turned up.

A face looking down.

Face

A face looking down.

Face of a Caucasian person.

Face

Face of a Caucasian person.

The arteries of the face and head. Labels: 1, common carotid; 2, internal carotid; 3, external carotid; 4, occipital artery; 5, superior thyroid artery; 6, trapezius; 7, lingual artery; 8, sterno-mastoid; 9, facial artery; 10, temporal artery, dividing into anterior and posterior branches; 11, submental branch; 12, transverse facial artery 13, inferior labial branch; 15, inferior coronary branch; 17, superior coronary branch; 19, lateral nasal branch; 21, angular branch.

Arteries of the Face and Head

The arteries of the face and head. Labels: 1, common carotid; 2, internal carotid; 3, external carotid;…

Nerves of the face and scalp. Labels: 1, attrahensaurem; 2, anterior belly occipito-frontalis; 3, auriculo-temporal nerve; 4, temporal branches of facial nerves; 5, attolens aurem; 6, supra-trochlea; 7, posterior belly occipito-frontalis; 8, supra-orbital; 9, retrahens aurem; 10, temporal branch of orbital nerve; 11, small occipital nerve; 12, malar branches of facial nerve; 13, posterior auricular nerve; 14, malar branch of orbital; 15, great occipital; 16, infra-orbital branches; 17, facial nerve; 18, nasal nerve; 19, cervico-facial division of facial; 20, infra-orbital branches; 17, facial nerve; 18, nasal nerve; 19, cervico-facial division of facial; 20, infra orbital nerve; 21, branches to digastric and stylo-hyoid; 22, temporo-facial division; 23, great auricular; 24, buccal branches of facial; 25, trapezius; 26, buccinator nerve; 27, splenius capitis; 28, masseter; 29, sterno-mastoid; 30, supra-maxillary branches of facial nerve; 31, superficial cervical nerve; 32, mental nerve; 33, platysma; 34, infra-maxillary branches of facial nerves.

Nerves of the Face and Scalp

Nerves of the face and scalp. Labels: 1, attrahensaurem; 2, anterior belly occipito-frontalis; 3, auriculo-temporal…

This illustration shows a method of applying a bandage to the face.

Face Bandage

This illustration shows a method of applying a bandage to the face.

Perspective of the face.

Face Perspective

Perspective of the face.

Perspective of the face.

Face Perspective

Perspective of the face.

An illustration of a face with two flutes and a crown of olive leaves.

Face with Two Flutes

An illustration of a face with two flutes and a crown of olive leaves.

Showing the development of the face. F.N.P., Part formed from the frontonasal process; L, from its lateral and M., from its mesial parts; MAX., formed by the maxillary process; MAN., formed by the mandibular process.

Development of the Face

Showing the development of the face. F.N.P., Part formed from the frontonasal process; L, from its lateral…

An illustration of a girl's face.

Girl's Face

An illustration of a girl's face.

The shield of a knight of the time of Edward II. The lion's face is a common charge in heraldry.

Heraldic Shield with a Lion's Face

The shield of a knight of the time of Edward II. The lion's face is a common charge in heraldry.

This is a male face shown with a bald head.

Male Face

This is a male face shown with a bald head.

This is a male face shown with a bald head. The head is tilted slightly backwards.

Male Face

This is a male face shown with a bald head. The head is tilted slightly backwards.

This is a male face shown with a bald head. The head is tilted backwards.

Male Face

This is a male face shown with a bald head. The head is tilted backwards.

This is a male face shown with a bald head. The head is tilted forwards.

Male Face

This is a male face shown with a bald head. The head is tilted forwards.

Anterior portion of mesial sagittal section of child's head, probably of about three year.

Mesial Sagittal Section of Child's Face

Anterior portion of mesial sagittal section of child's head, probably of about three year.

"Some nerves of the face." &mdash;Davison, 1910

Nerves of the face

"Some nerves of the face." —Davison, 1910

Nerves of the head, face, and neck.

Nerves of the Face

Nerves of the head, face, and neck.

The arteries of the face and scalp. The muscle tissue of the lips must be supposed to have been cut away, in order to show the course of the coronary arteries.

Facial Arteries

The arteries of the face and scalp. The muscle tissue of the lips must be supposed to have been cut…

This illustration shows a method of applying a bandage to the face to cover an eye.

Facial Bandage

This illustration shows a method of applying a bandage to the face to cover an eye.

This illustration shows a method of applying a bandage to the face to cover both eyes.

Facial Bandage

This illustration shows a method of applying a bandage to the face to cover both eyes.

Muscles of the face, jaw and neck. 1, longus colli; 2, rapezius; 3, sterno-hyoid; 4, sterno-mastoid; 5, erico-thyroid; 6, trapezius; 7, constrictor of pharynx; 8, sterno-mastoid; 9, digastric; 10, attrahens aurem; 11, mylo-hyoid; 12, masseter; 13, depressor oof lower lip; 15, orbicularis oris; 17, levator of upper lip; 19, levator of angle of mouth; 21, orbicularis palpebrarum.

Facial Muscles

Muscles of the face, jaw and neck. 1, longus colli; 2, rapezius; 3, sterno-hyoid; 4, sterno-mastoid;…

The distribution of nerves on the side of the face.

Facial Nerves

The distribution of nerves on the side of the face.

"Distribution of nerves on the side of the face." &mdash; Richardson, 1906

Facial Nerves

"Distribution of nerves on the side of the face." — Richardson, 1906

The forehead is the region between the eyebrows and hairline on a person's face.

Forehead

The forehead is the region between the eyebrows and hairline on a person's face.

"Fig. 62 Skull of common fowl, enlarged. from nature by Dr. R.W. Shufeldt, U.S.A. The names of bones and some other parts are printed, requiring no explanation; but observe the following points: The distinction of none of the bones composing the brain-case (the upper back expanded part) can be found in a mature skull. The brain is contained between the occipital, sphenoidals, squamosals, parietals and part of frontal; the ethmoidals belong to the same group of cranial bones proper. All other bones, excepting the three otic ear-bones, are bones of the face and jaws. The lower jaw, of five bones, is drawn detached; it articulates by the black surface marked articular with the prominence just above- the quadratic bone. Observe that from this quadrate a series of bones quadrato-jugal, jugal, maxillary-makes a slender rod running to the premaxillary; this is the zygoma, or jugal bar. Observe from the quadrate also another series, composed of pterygoid and palatine bones, to the premaxillary; this is the pterygo-palatine bar; it slides along a median fixed axis of the skull, the rostrum, which bears the loose vomer at its end. The under mandible, quadrate, pterygoid, and vomer are the only movable bones of this skull. But when the quadrate rocks back and forth, as it does by its upper joint, its lower end pulls and pushes upon the upper mandible, by means of the jugal and pterygo-palatine bars, setting the whole scaffolding of the upper jaw in motion. This motion hinges upon the elasticity of the bones of the forehead, at the thin place just where the reference-lines from the words "lacrymal" and "mesethmoid" cross each other. The dark oval space behind the quadrate is the external orifice of the ear; the parts in it to which the three reference-lines go are diagrammatic, not actual representations; thus, the quadrate articulates with a large pro-otic as well as with the squamosal. The great excavation at the middle of the figure, containing the cirlet of the unshaded bones, is the left orbital cavity, orbit, or socket of the eye. The mesethmoid includes most of the background of this cavity, shaded diagonally. The upper one of the two processes of bone extending into it from behind is post-frontal or sphenotic process; the under one (just over the quadrate) is the squamosal process. A bone not shown, the presphenoid, lies just in front of the oval black space over the end of basisphenoid. This black oval is the optic foramen, through which the nerve of sight passes from the brain-cavity to the eye. The black dot a little behind the optic foramen is the orifice of exit of a part of the trifacial nerve. The black mark under the letters "on" of the word "frontal" is the olfactory foramen, where the nerve of smell emerges from the brain-box to go to the nose. The nasal cavity is the black space behind nasal and covered by that bone, and in the oval blank before it. The parts of the beak covered by horn are only premaxillary, nasal, and dentary. The condyle articulates with the first cervical vertebra; just above it, not shown, is the foramen magnum, or great hole through which the spinal medulla, or main nervous cord, passes from the spinal column. The basioccipital is hidden, excepting its condyle; so is much of the basisphenoid. The prolongation forward of the basisphenoid, marked "rostrum," and bearing the vomer at its end, is the parasphenoid, as far as its thickened under border is concerned. Between the fore end of the pterygoid and the basisphenoidal rostrum, is the site of the basipterygoid process, by which the bones concerned articulate by smooth facets; further forward, the palatines ride freely upon the parasphenoidal rostrum. In any passerine bird , the vomer would be thick in front, and forked behind, riding like the palatine upon the rostrum. The palatine seems to run into the maxillary in this view; but it continues on to premaxillary. The maxillo-palatine is an important bone which cannot be seen in the figure because it extends horizontally into the paper from the maxillary about where the reference life "maxillary" goes to that bone. The general line from the condyle to the end of the vomer is the cranial axis, basis cranii, or base of the cranium. This skull is widest across the post-frontal; next most so across the bulge of the jugal bar." Elliot Coues, 1884

Skull of a Common Fowl

"Fig. 62 Skull of common fowl, enlarged. from nature by Dr. R.W. Shufeldt, U.S.A. The names of bones…

The frontal bone at birth. Developed from two lateral halves.

Frontal Bone at Birth

The frontal bone at birth. Developed from two lateral halves.

Girl's face looking left.

Girl

Girl's face looking left.

Girl with bow.

Girl

Girl with bow.

A girl standing with her hands to her face, crying.

Girl Crying

A girl standing with her hands to her face, crying.

A young girl posing.

Girl Posing

A young girl posing.

Little girl with hat and ribbons.

Girl with Hat

Little girl with hat and ribbons.

A decorative divider with Greek statues, musical instruments, and flowers.

Greek Divider

A decorative divider with Greek statues, musical instruments, and flowers.

A decorative divider with griffins, Greek statues, and cornucopias.

Greek Divider

A decorative divider with griffins, Greek statues, and cornucopias.

An illustration of a face.

Head

An illustration of a face.

Sagittal median section of the head and neck. The head is thrown backward into complete extension which explains the relations between the lower jaw and the hyoid bone as seen in the figure.

Sagittal Section of the Head and Neck

Sagittal median section of the head and neck. The head is thrown backward into complete extension which…

Section of head and neck from front to back. Labels: 1, windpipe; 2, larynx; 3, spinal marrow; 4, pharynx; 5, tongue or hyoid bone; 6, epiglottis; 7, tongue; 8, hard palate; 9, soft palate; 10; bridge of the nose; 11, frontal cavity; 12; sphenoid cavity; 13, nasal cavity; 14, skin of skull; 15, bony skull; 16, hypophisis; 17, corpus callosum; 18, septum lucidum; 19, straight sinus; 20, cerebellum; 21 cerebrum; 22, lobes of medulla; 23, pons varolii; 24, medulla oblongata; 25, zone of the epistropheus; 26, vertebrae; 27, spinal continuation of the vertebrae.

Section of the Head and Neck

Section of head and neck from front to back. Labels: 1, windpipe; 2, larynx; 3, spinal marrow; 4, pharynx;…

Distribution of sensory nerves to the head and neck. Labels: Ophth, ophthalmic division of the fifth nerve; St, supratrochlear branch; S.O, supra-orbital branch; I.T, infratrochlear branch; L, lachrymal branch; N, external nasal branch; Sup.Max, superior maxillary division; T, temporal branch; M, malar branch; I.O, infra-orbital branch; Inf.Max, inferior maxillary branch; M, mental branch; C2, 3, branches of the second and third cervical nervs; G.O, great occipital nerve; S.O, small occipital nerve; G.A, great auricle nerve; S.C, superficial cervical nerve; C3, least occipital nerve; 4, 5, 6, posterior primary division of 4th, 5th, 6th cervical nerve.

Sensory Nerves to the Head and Neck

Distribution of sensory nerves to the head and neck. Labels: Ophth, ophthalmic division of the fifth…

This illustration shows a method of applying a bandage to the head.

Head Bandage

This illustration shows a method of applying a bandage to the head.

Section of the head immediately below the orbits, at the level of Reid's base line exposing the maxillary sinus.

Cross Section of Head Exposing Maxillary Sinus

Section of the head immediately below the orbits, at the level of Reid's base line exposing the maxillary…

The side angle view of a person's head.

Head Profile

The side angle view of a person's head.

Section of the head through the nasopharynx.

Cross Section of Head Through the Nasopharynx

Section of the head through the nasopharynx.

The muscles of the face and scalp.

Muscles of the Head

The muscles of the face and scalp.