An ancient Assyrian wall relief, depicting the symbol of a winged bull with the head of a human male.

Winged Bull

An ancient Assyrian wall relief, depicting the symbol of a winged bull with the head of a human male.

The Assumption and the Coronation of the Virgin is a woodcut created by Albrecht Dürer in 1510. It is part of a series called "Life of the Virgin". It depicts Mary being crowned by God and Jesus among the clouds. It shows heaven and earth, angels and mortals. A woodcut is created by carving an image on a wooden block and rolling ink over that surface and then printing it on paper.

The Assumption and the Coronation of the Virgin

The Assumption and the Coronation of the Virgin is a woodcut created by Albrecht Dürer in 1510.…

"Showing how the image of an object which is seen is formed on the retina of the eye." —Croft 1917

Eye Focusing on Object

"Showing how the image of an object which is seen is formed on the retina of the eye." —Croft…

Device used for contact printing that holds a negative against the photographic paper. The paper is exposed by light from an external light

Printing Frame

Device used for contact printing that holds a negative against the photographic paper. The paper is…

"If the object a be placed obliquely before the convex mirror, then the converging rays from its two extremities falling obliquely on its surface, would they prolonged through the mirror, meet at the point c, behind it. But instead of being thus continued, they are thrown back by the mirror in less convergent lines, which meet the eye at e, it being, as we have seen, one of the properties of this mirror, to reflect converging rays less convergent than before." -Comstock 1850

Curved Image

"If the object a be placed obliquely before the convex mirror, then the converging rays from its two…

"Slit A is a very small opening. The light coming from the soldier on the right shines through the slit in straight lines making the image of the soldier inverted on wall W." —Quackenbos 1859

Inverted Image

"Slit A is a very small opening. The light coming from the soldier on the right shines through the slit…

"Showing a system with chromatic difference of spherical aberration. O" ₌ image of O for red light; O'" for blue. The system is under—corrected for red, and over—corrected for blue rays." —Encyclopaedia Britannica, 1910

Light Correction of Blue and Red Lights using Spherical Lens

"Showing a system with chromatic difference of spherical aberration. O" ₌ image of O for red light;…

"Let a candle c, be placed on the inside of a box or tube, so that its light may pass through the plano-convex lens n, and strongly illuminate the object o. This object is generally a small transparent painting on a slip of glass, which slides through an opening in the tube. In order to show the figures in the erect position, these paintings are inverted, since their shadows are again inverted by the refraction of the convex lens m." —Comstock, 1850

Magic Lantern

"Let a candle c, be placed on the inside of a box or tube, so that its light may pass through the plano-convex…

"The focus of each point chose may be determined by tracing two rays from the point, and locating their real or apparent intersection after reflection by the mirror. The two rays most convenient for this purpose are teh oen that lies along the axis fo the point, and the one that lies parallel to the principal axis of the mirror." -Avery 1895

Concave Mirror with Image and Focus

"The focus of each point chose may be determined by tracing two rays from the point, and locating their…

"When the object is at a distance from the mirror somewhat greater than the center of curvature, as beyond C, the image is real, inverted, smaller than the object, and at a distance from the mirror greater than that of the principle focus and less than that of the center of curvature, as between F and C." -Avery 1895

Image Beyond the Curvature of a Concave Mirror

"When the object is at a distance from the mirror somewhat greater than the center of curvature, as…

"To explain this, let us suppose that the arrow a, is diminished by reflection from the convex surface, so that its image appearing a d, with the eye at c, shall seem as much smaller in proportion to the object, as d is less than a. Now keeping the eye at the same distance from the mirror, withdraw the object, so that it shall be equally distant with the eye, and the image will gradually diminish, as the arrow is removed." -Comstock 1850

Convex Mirror

"To explain this, let us suppose that the arrow a, is diminished by reflection from the convex surface,…

"Rays from an object showing the reproduction of an image in a convex mirror." -Avery 1895

Convex Mirror Reproducing an Image of an Arrow

"Rays from an object showing the reproduction of an image in a convex mirror." -Avery 1895

"Parallel rays strike the convex mirror, reflect, and diverge as if they had originated from a virtual focus inside the mirror. Focus F is located between the surface of the mirror and the mirror's center if it were a full body sphere." —Quackenbos 1859

Reflection by Convex Mirrors

"Parallel rays strike the convex mirror, reflect, and diverge as if they had originated from a virtual…

"The construction for the image produced by a plane mirror depends upon the fact that the image of the object may be located by locating the images of a number of well chosen points in the surface of the object." -Avery 1895

Object in Plane Mirror

"The construction for the image produced by a plane mirror depends upon the fact that the image of the…

"Regular reflection results from the incidence of radiant energy upon a polished surface. When a beam of light falls upon a mirror, the greater part of it is reflected in a definite direction as is illustrated, and forms an image of the object from which it came. A perfect mirror would be invisible." -Avery 1895

Regular Reflection

"Regular reflection results from the incidence of radiant energy upon a polished surface. When a beam…

"Showing how an object is refracted through a biconvex lens." -Avery 1895

Object Refracted through Biconvex Lens

"Showing how an object is refracted through a biconvex lens." -Avery 1895

This sculpture depicts a female that has been layed to rest and her last earthly image is of the spirits who are welcoming her.

Sculpture

This sculpture depicts a female that has been layed to rest and her last earthly image is of the spirits…

"O' is the virtual image of O formed at a spherical surface of centre C and radius CS." —Encyclopaedia Britannica, 1910

Virtual Image Formed on Spherical Surface

"O' is the virtual image of O formed at a spherical surface of centre C and radius CS." —Encyclopaedia…

A column depicting carvings and images of life in Thebes.

Column from Thebes

A column depicting carvings and images of life in Thebes.