Safety glasses are usually made with shatter-resistant plastic lenses to protect the eye from flying debris. Although safety lenses may be constructed from a variety of materials of various impact resistance, certain standards suggest that they maintain a minimum 1 millimeter thickness at the thinnest point, regardless of material. Safety glasses can vary in the level of protection they provide.

Round Safety Glasses

Safety glasses are usually made with shatter-resistant plastic lenses to protect the eye from flying…

A hand drawing a violin-bow across the edge of a goblet half-filled with water.

Hand with bow and glass

A hand drawing a violin-bow across the edge of a goblet half-filled with water.

This door handle is in a Gothic design and lined with glass and china.

Door Handle

This door handle is in a Gothic design and lined with glass and china.

A pair of hands holding a glass tube filled with a dark liquid.

Hands with tube

A pair of hands holding a glass tube filled with a dark liquid.

"It consists of a brass dish A and two glass globes B and C. The dish communicates with the lower part of the globe C by means of a long tube D, and another tube E connects the two globes. A third tube passes through the dish A to the lower part of the globe B. This last tube being taken out, the globe B is partially filled with water, the tube is then replaced, and water is poured into the dish. The water flows through tube D into the lower globe, and expels the air, which is forced into the upper globe. The air thus compressed acts on the water and makes it jet out as represented in the figure." — Hallock, 1905

Hero's Fountain

"It consists of a brass dish A and two glass globes B and C. The dish communicates with the lower part…

This glass holder is intended to hold glass cups while drying, the holder features a drip pan at the bottom.

Glass Holder

This glass holder is intended to hold glass cups while drying, the holder features a drip pan at the…

"It is composed of a hollow ball of glass, or metal, with a graduated scale rising from its upper part, which serves to balance it in the fluid." -Comstock 1850

Hydrometer

"It is composed of a hollow ball of glass, or metal, with a graduated scale rising from its upper part,…

The antique glass lachrymatory has a tear-like profile.

Antique Glass Lachrymatory

The antique glass lachrymatory has a tear-like profile.

"A double convex lens of crown-glass may be combined with a plano-convex lens of flint-glass so as to overcome the dispersive effect for some of the colors without overcoming the converging effect." -Avery 1895

Achromatic Lens

"A double convex lens of crown-glass may be combined with a plano-convex lens of flint-glass so as to…

"...let LN represent a glass biconvex lens, with centres of curvature at C and C', and AB, the incident ray." -Avery 1895

Refraction of Light through Bi Convex Lens

"...let LN represent a glass biconvex lens, with centres of curvature at C and C', and AB, the incident…

"a, prism; b, plane glass; c, spherical lens; d, double-convex; e, plano-convex, f, double-concave; g, plano-concave; h, meniscus; i, concavo-convex lenses." -Comstock 1850

Lenses of Various Forms

"a, prism; b, plane glass; c, spherical lens; d, double-convex; e, plano-convex, f, double-concave;…

"...consists of a glass jar coated inside and outside with tinfoil, or some other thin sheet metal, except three or four inches at top, lef uncoated for insulation between the coated surfaces. This jar is closed with an insulating cover, through which a brass rod extends to the inside coating, and terminates above in a ball." -Atkinson 1903

Leyden Jar

"...consists of a glass jar coated inside and outside with tinfoil, or some other thin sheet metal,…

"The most common and, for many purposes, the most convenient form of condenser is the Leyden jar. This consists of a glass jar, coated within and without for about two-thirds its height with tinfoil, and a metallic rod that communicates by means of a small chain with the inner coat, and terminates above in a knob or a disk." — Avery, 1895

Diagram of a Leyden jar

"The most common and, for many purposes, the most convenient form of condenser is the Leyden jar. This…

A graceful speaker.

Man with glass

A graceful speaker.

"Five kinds of glass are made: flint glass, or crystal; crown glass, broad sheet glass, bottle, or green glass, and plate glass." —The Popular Cyclopedia, 1888

Glass manufacturing

"Five kinds of glass are made: flint glass, or crystal; crown glass, broad sheet glass, bottle, or green…

This Medieval Tile circle pattern is a stained glass design. It the oldest process of fitting together pieces of colored glass in a mosaic style.

Medieval Tile Pattern

This Medieval Tile circle pattern is a stained glass design. It the oldest process of fitting together…

This medieval tile pattern is a stained glass design. It the oldest process of fitting together pieces of colored glass in a mosaic style.

Medieval Tile Pattern

This medieval tile pattern is a stained glass design. It the oldest process of fitting together pieces…

This medieval tile circle pattern is a stained glass design. It the oldest process of fitting together pieces of colored glass in a mosaic style.

Medieval Tile Pattern

This medieval tile circle pattern is a stained glass design. It the oldest process of fitting together…

This medieval tile pattern is a stained glass design. It the oldest process of fitting together pieces of colored glass in a mosaic style.

Medieval Tile Pattern

This medieval tile pattern is a stained glass design. It the oldest process of fitting together pieces…

This medieval tile pattern is a stained glass design. It the oldest process of fitting together pieces of colored glass in a mosaic style.

Medieval Tile Pattern

This medieval tile pattern is a stained glass design. It the oldest process of fitting together pieces…

This medieval tile pattern is a stained glass design. It the oldest process of fitting together pieces of colored glass in a mosaic style.

Medieval Tile Pattern

This medieval tile pattern is a stained glass design. It the oldest process of fitting together pieces…

This medieval tile pattern is a stained glass design. It the oldest process of fitting together pieces of colored glass in a mosaic style.

Medieval Tile Pattern

This medieval tile pattern is a stained glass design. It the oldest process of fitting together pieces…

"A plate of glass about 2.5 inches square is ruled with twenty-one lines in one direction .1 inch apart, and two lines in the other direction 2 inches apart. The extreme lines of the set therefore form a perfect square of 2 inches. These lines are ruled with exceeding accuracy and care, but provision is left for ascertaining any errors that remain either as to distance or want of perfect squareness." —The Encyclopedia Britannica, 1903

Micrometer

"A plate of glass about 2.5 inches square is ruled with twenty-one lines in one direction .1 inch apart,…

"Procure an open organ-pipe, at least one side of which is made of glass. While the pipe is emitting its fundamental tone, lower a small ring with a paper bottom, on which a little fine sand has been strewn, as shown. Just inside the upper part of the pipel, the sand dances...its motion becoming less energetic as the ring approaches the middle of the pipe." -Avery 1895

Organ Pipe

"Procure an open organ-pipe, at least one side of which is made of glass. While the pipe is emitting…

Perlite. Thin section under the microscope, enlarged 30 diameters.

Perlite

Perlite. Thin section under the microscope, enlarged 30 diameters.

This Antique glass phiale is a slender vessel without handles. It has an elongated body with a long narrow neck.

Antique Glass Phiale

This Antique glass phiale is a slender vessel without handles. It has an elongated body with a long…

The Egyptian phiale with cover is a slender vessel without handles. It has an elongated body with a long narrow neck made out of clay or glass.

Egyptian Phiale

The Egyptian phiale with cover is a slender vessel without handles. It has an elongated body with a…

This Venetian pipe-spout pot is a 16th century design made out of glass.

Venetian Pipe-Spout Pot

This Venetian pipe-spout pot is a 16th century design made out of glass.

This Venetian pipe-spout pot is a 16th century design made out of glass.

Venetian Pipe-Spout Pot

This Venetian pipe-spout pot is a 16th century design made out of glass.

"The glass roof is commonly designed so as to form a uniform plane or slope from back to front in lean-to houses, and form center to sides in span-roofed houses. In some cases, however, the roof sashes are fitted up on the ridge-and-furrow principle invented by Sir Joseph Paxton." — Encyclopedia Britannica, 1893

Plant House

"The glass roof is commonly designed so as to form a uniform plane or slope from back to front in lean-to…

"The tightly fitted piston at the top of a glass vessel of water is driven down. The contained liquid is compressed and the pressure equally distributed through the glass and the water flows out of the tubes along the sides." —Quackenbos 1859

Pressure of Liquids

"The tightly fitted piston at the top of a glass vessel of water is driven down. The contained liquid…

A solid having two parallel polygonal bases connected by triangular faces.

Prismatoid

A solid having two parallel polygonal bases connected by triangular faces.

"Fresnel next conceived the admirable improvement of employing the principle of "total" or internal reflexion by glass prisms. The ray Fi falling on a prismoidal ring, ABC, is refracted and bent in the direction iR, and falling on the side AC, at an angle of incidence greater than the critical, is totally relfected in the direction Re, and, impinging on the side BC at e, it undergoes a second refraction, and emerges horizontally. The highest ray FA after refraction by AB and reflexion by AC must (in order to avoid superfluous glass) pass along AB, and after a second refraction at B emerge horizontally. The lowest ray FB after refraction by AC and a second refraction by BC also emerge horizontally." —The Encyclopedia Britannica, 1910

Reflecting Prism

"Fresnel next conceived the admirable improvement of employing the principle of "total" or internal…

"About two feet away from an air thermometer, place an inverted flower pot. Midway between the two, place a board or glass screen that reaches from the table to a height of several inches above teh bulb of the air theremometer. Upon the flower pot, place a very hot brick. Notice that the heat of the brick has little effect upon the thermometer. Then hold a sheet of tin plate over the screen so that energy radianted obliquely upward from the brick may be reflected obliquely downward toward the thermometer. By properly adjusting the position of the reflector, the thermometer may be quickly affected." -Avery 1895

Heat Reflection

"About two feet away from an air thermometer, place an inverted flower pot. Midway between the two,…

"Illustrating refraction of light from a source through glass, and the appropriate angles of refraction." —Croft 1917

Refraction of Light through Glass

"Illustrating refraction of light from a source through glass, and the appropriate angles of refraction."…

"Let a represent a, b water, and c a piece of glass. The ray d, striking each medium in a perpendicular direction." -Comstock 1850

Refraction, air, water, glass

"Let a represent a, b water, and c a piece of glass. The ray d, striking each medium in a perpendicular…

"Thus, when erher waves that constitute light are transmitted through glass, they are hindered by the molecules of the glass, and impart some of their motion to those molecules' i.e., a part of the light is absorbed. When a beam of light, as represented by ABC moves forward in the air, the wave-front, MN, continues parallel to itself and moves forward in a straight line. As the wave front advances, A strikes the glass first, and is retarted, the retardation of B and C later change the direction of the rays." -Avery 1895

Explanation of Refraction

"Thus, when erher waves that constitute light are transmitted through glass, they are hindered by the…

"Let the medium b be glass, and the medium c, water. The ray a, as it falls upon the medium b, is refracted towards the perpendicular line e d; but when it enters the water, whose refractive power is less than that of glass, it is not bent so near the perpendicular as before, and hence it is refracted from, instead of towards the perpendicular line, and approaches the originial direction of the ray a g, when passing through the air." -Comstock 1850

Refraction, glass and water

"Let the medium b be glass, and the medium c, water. The ray a, as it falls upon the medium b, is refracted…

"This instrument consists of a glass tube of narrow bore, 16 to 17 inches long, to which is blown a glass globe 3 to 4 inches in diameter. This tube is partially filled with some colored fluid which confines the air in the flobe, a wide reservoir at the other end of the tube allows the fluid to accumulate without sensible change of level. The stand of the instrument consists of two pieces hinged together, so that the tube can be laced at a small inclination to the horizon." — Encyclopedia Britannica, 1893

Reibungselectricitat

"This instrument consists of a glass tube of narrow bore, 16 to 17 inches long, to which is blown a…

"A Retort is a vessel in whose chamber an object is subjected to distillation or decomposition by heat, a neck conducting off the volatile products. The retort of the chemical laboratory is a vessel of glass, platinum, porcelain, or other material. It is bottle-shaped, having a long neck attached, in which the products of the distillation are condensed, and from which they pass into the receiver. The retort of the gas works is a cylinder or segment of a cylinder, formed of clay or iron."—(Charles Leonard-Stuart, 1911)

Retort

"A Retort is a vessel in whose chamber an object is subjected to distillation or decomposition by heat,…

This spice-frame salt-cellar is a 18th century design made out of glass.

Spice-Frame Salt-Cellar

This spice-frame salt-cellar is a 18th century design made out of glass.

"Sand Blast is one of the most wonderful uses of sand, by means of which glass, stone, metals, or any other hard substance may be cut or engraved. If a stream of sharp sand be let fall from a high box (as high as the ceiling of a room) through a tube on to a plate of glass held under it, the sand will cut away little grains of the glass till at length the whole surface will be cut or scratched and it will look like ground glass. If, instead of cutting the glass all over, it is wanted to engrave a pattern or figure on it, the workman has only to cover the parts of the glass which he does not want cut with a stencil plate made of leather, rubber, paper, wax, etc., for the sand will not cut any soft substance. Metals and stones may also be cut by means of the sand blast, which will not only scratch the surface, but will cut it away to any depth."—(Charles Leonard-Stuart, 1911)

Sand Blast Apparatus

"Sand Blast is one of the most wonderful uses of sand, by means of which glass, stone, metals, or any…

"The ordinary sheet-metal shears merely resemble very powerful scissors, and, their action being quite local, they serve well for dividing the plates or other thin sheets for which alone they are suitable." — Encyclopedia Britannica, 1893

Sheet-metal Shears

"The ordinary sheet-metal shears merely resemble very powerful scissors, and, their action being quite…

Water flows frow the higher glass through the tub and into the lower glass.

Siphon

Water flows frow the higher glass through the tub and into the lower glass.

"Apparatus used that will show changes in the flame upon the glass sheet M, when sound is introduced into the tube at A." -Avery 1895

Flame Sonometer

"Apparatus used that will show changes in the flame upon the glass sheet M, when sound is introduced…

"Professor Swan's Designs.—Among several ingenious arrangements and new forms of agents proposed by Professor Swan is the mode of sending rays from prisms through interstices left between other prisms placed in front, and also a form of agent which he termed the triesoptric prism, in which the rays would undergo two refractions and three reflexions. a are the front and b the triesoptric prisms. The two upper and lower prisms a are constructed of flint glass of high refractive power. It will be observed from the drawing that this ingenious arrangement is nevertheless open to objection, for cones of light of 30 degrees in front and of 65 degrees at the back are lost through the interstices." —The Encyclopedia Britannica, 1910

Swans Designs

"Professor Swan's Designs.—Among several ingenious arrangements and new forms of agents proposed…

"Siemen's Continuous Tank Furnace." — Encyclopedia Britannica, 1893

Tank Furnace

"Siemen's Continuous Tank Furnace." — Encyclopedia Britannica, 1893

"Siemen's Continuous Tank Furnace." — Encyclopedia Britannica, 1893

Tank Furnace

"Siemen's Continuous Tank Furnace." — Encyclopedia Britannica, 1893

An illustration of a tankard.

Tankard

An illustration of a tankard.

An illustration of a tankard.

Tankard

An illustration of a tankard.

"The spy-glass or terrestrial telescope avoids the inversion of the image by the interposition of two double-convex lenses, m and n, between the objective and eyepiece. The rays diverging from the inverted image at I cross between m and n, and form an erect magnified, virtual image at ab." — Avery, 1895

Terrestrial telescope

"The spy-glass or terrestrial telescope avoids the inversion of the image by the interposition of two…

Apparatus for breaking a plate of glass by torsion, with an example of results produced.

Torsion Apparatus

Apparatus for breaking a plate of glass by torsion, with an example of results produced.

Arrangement of fractures in a large plate of glass which was broken by torsion.

Glass Broken by Torsion

Arrangement of fractures in a large plate of glass which was broken by torsion.

This vase is found in London, England and is made out of glass and silver.

Vase

This vase is found in London, England and is made out of glass and silver.

This vase is found in London, England and is made out of glass and silver.

Vase

This vase is found in London, England and is made out of glass and silver.

The vase is an open container, often used to hold cut flowers. It can be made from a number of materials including ceramics and glass. The vase is often decorated and thus used to extend the beauty of its contents.

Bottle Type Vase

The vase is an open container, often used to hold cut flowers. It can be made from a number of materials…

A drinking glass, or simply glass, is a drinking vessel, usually made from glass or plastic. Glasses are often clear, but sometimes are colored, or printed or etched with decorations. Compared with a cup, a glass stands taller without a handle and usually holds more liquid.

Star Shaped Glass Vessel

A drinking glass, or simply glass, is a drinking vessel, usually made from glass or plastic. Glasses…

"Support, as shown, a glass or brass plate, square or round, and strew it evenly with fine sand. Place the finger at any point of the edge of the plate, so as to form a node there, and draw a violin bow at a point properly chosen. The sand immediately begins to dance on the plate and arrange itself along nodal lines. By changing the nodal points and bowing properly, other sand-figures may be produced, one of which is shown." -Avery 1895

Vibrating Plates

"Support, as shown, a glass or brass plate, square or round, and strew it evenly with fine sand. Place…

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…

Two windows together.

Coupled Windows

Two windows together.