Illustrated Glossary of Lamp Terms

Below is a list of terms commonly used to describe lamps and other lighting devices, their component parts, and factors affecting their condition. This list is undoubtedly incomplete and should be considered a "work in progress." It will be amended regularly. I welcome your suggestions for corrections, changes or additions.

The Glossary of Terms is alphabetized. Any terms that appear in green are links to pictures or illustrations that graphically depict that particular term. The Glossary is quite lengthy and I have tried to make it as easy as possible to navigate through it. You can easily get back to the index from any letter heading, or back to the top of the page to the Main Navigation Buttons.

INDEX

A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Top of Page A Index

Acid Etching -- The process of etching the surface of glass with hydrofluoric acid. Acid-etched decoration is produced by covering the glass with an acid-resistant substance such as wax, through which the design is scratched. A mixture of dilute hydrofluoric acid and potassium fluoride is then applied to etch the exposed areas of glass.
Angle Lamp -- The trade name for a lamp manufactured by The Angle Manufacturing Company designed to eliminate the undershadow produced by most lamps. The burners were set at an angle and were fitted with bowl shaped elbows topped with conical chimney-shades.
Annealing -- The process of slowly cooling a completed object in an auxiliary part of the glass furnace, or in a separate furnace. This is an integral part of glassmaking because if a hot glass object is allowed to cool too quickly, it will be highly strained by the time it reaches room temperature; indeed, it may break as it cools.
Annealing Crack -- A defect that occurs during the glass manufacturing process (during cooling) and generally results in a fine, hairline crack. Often, the crack does not go through the glass.
Argand -- The burner type designed by Ami Argand which employs a circular wick held between to concentric metal tubes and uses a chimney and improved air flow design to produce a brighter, more efficient flame. Also refers to the early style of lamp using the Argand principle with a centrally located oil fount feeding the burner that is mounted on an arm away from the fount. The more recent student lamp is a revival of this early design.
Astral -- A lamp style employing an Argand burner and characterized by air intake holes near the base of the fount. Usually all metal lamps with pear-shaped founts and bases that often include marble or other stone.

Top of Page B Index
Base -- The bottom portion of a lamp, or foot, upon which the lamp rests.
Blaze Hole -- The opening in the deflector or burner cone through which the flame passes.
Blown Glass -- Glass that is made on a blowpipe, formed and shaped by hand.
Bubbles -- Air pockets trapped within the glass. Quite common in early glass. Small bubbles are frequently referred to as seeds.
Burning Fluid -- A mixture of alcohol and turpentine, used as lamp fuel in the 19th century. Burning fluid, which was dangerously explosive, was replaced by kerosene in the late 1850s.
Burst Bubble -- A bubble that is broken open on one side, resulting in a 'hole' in the surface that does not go through.
Bracket Lamp -- Any variation of lamp designed to be mounted on a vertical surface and extend outward. Many are adjustable side-to-side and swing outward. Brackets can be made of brass, bronze, cast iron, etc. Founts can be either metal or glass. Many bracket lamps feature reflectors mounted behind the lamp to increase the light output.
Bruise -- Usually an arc- or star-shaped area of damage with the piece of glass still intact. Bruises usually result from an impact of substantial force, such as the article being dropped.
Burner -- The apparatus of a lamp that "produces" the flame. Usually consists of a metal enclosure, a wick to supply the (liquid) fuel, and a series of holes to provide air for combustion, and a method of adjusting the wick. Additional air flow may be controlled by the use of a chimney.
Burner Cone -- Another name for the deflector, see below.
Burner Tube -- On a Student or Agrand lamp, the vertical member that houses the burner and often supports the shade.

Top of Page C Index
Canopy -- The part of a lighting fixture the mounts to the ceiling. In a pull-down hall lamp fixture, the part that hangs from the ceiling and contains the pulleys.
Cased Glass -- Glass formed by layering glass of varying colors together. Usually two colors, sometimes more. In founts, it is often wheel cut to produce geometric designs. Sometimes referred to as "overlay."
Ceiling Extension -- The mechanism of a hanging lamp that allows the lamp to be raised and lowered for service or lighting. Often consists of a set of chains that are wound by a heavy spring. Most have a decorative cover. Commonly called "motors" or "winders".
Center or Central Draft -- A burner type, using the Argand principle, characterized by a hollow tube running through the center of the fount or lamp. Generally uses a flame spreader to diffuse the air.
Chip -- Damage occurring after manufacture whereby a piece of the class has been removed.
Chimney -- Usually a glass (sometimes mica or even metal) enclosure that helps control the flow of air to and around a lamp burner.
Chimney-Shade -- Used to describe any glass appurtenance which combines the functions of the chimney and shade into one unit.
Cigar Lighter -- A (usually) decorative oil lamp which functioned as a method for gentleman to light their cigars. Usually had a small flame enclosed by a small shade. Removable lighters or dips were then ignited from the flame and used to light the cigar.
Cold Blast -- A lantern design whereby only fresh air is fed to the flame. All hot air is vented out the top of the lantern. Produces a whiter light than the hot-blast lantern configuration.
Collar -- The metal ring or band, usually threaded, that allows the lamp burner to be attached to the lamp fount.
Composite -- A term used to describe a lamp comprised of more than one part or material. Commonly found with metal or decorated glass & china stems.
Connector -- The piece, usually metal (brass), that joins the lamp stem to the lamp fount. Can be threaded (Atterbury), pressed or cemented on with indentations (Hobbs) or dimples to hold it in place.
Copper-wheel Engraving -- A technique of decorating the surface of an object. Copper disks or wheels are rotated on a spindle. An abrasive mixed with oil is applied to the edge of the wheel. The wheel presses the abrasive against the glass so that it removes the surface by grinding.
Coronet -- A type of burner that takes a lip or flanged chimney. Specifically, the circular gallery into which the chimney is secured by a spring or set screw.
Crease -- A crisp, sharp bend in the metal. Often attempting to bend the metal back into its original position or shape causes it to break. Once the metal is straightened, evidence of a crease usually exists.
Crown -- On a hanging lamp, the decorative trim ring on the top of the shade, or the ring that secures (holds) the shade from the top.
Cutting -- A method of decorating glass whereby portions of the glass are removed by grinding and polishing.

Top of Page D Index
Dead Flame -- A lantern design whereby the airflow to the flame is strictly controlled, reducing the draft, and thereby reducing or eliminating flickering.
Dent -- A larger depression in the metal greater than �" in length.
Deflector -- The domed part of the burner which encloses the wick tube and wick. Directs air flow to the wick and helps control combustion, thus producing a stable flame.
Ding -- A small depression in the metal not more than �" long.
Dip -- The removable lighter from a cigar lighter lamp. Generally have a decorative "handle" or finial and a twisted wire end shaped like a cotton swab that is soaked in kerosene until lighted.
Double-Jack Chain -- A type of chain commonly used on hanging lamps that is characterized by s-shaped links folded tightly back over themselves for added strength. Often used in ceiling extension mechanisms and hall lamps.
Drip Cup -- On a Student lamp, the cup on the bottom of the burner tube that functions both as an air intake for the center draft burner, and as a catch basin for any drips of oil from within the draft tube.
Duplex -- A burner design which employs two flat wicks, side-by-side, to increase light output. Usually each wick is adjustable with its own thumb wheel.

Top of Page E Index
Embossed -- Any pattern or design that is pressed or molded into a piece. Term can apply to both metal and glass items.
Engraving -- A method of producing a design/pattern on glass whereby shallow cuts are made using copper cutting wheels and abrasives.
Etching -- A method of producing designs/patterns on glass whereby acids are used to remove part of the glass and make the design.
Expander -- A threaded metal ring which allows a lamp collar to accept the next larger size burner.
Extinguisher -- A mechanism incorporated into the burner design that allows the flame to be extinguished, generally by depressing a lever which raises a sleeve over the wick tube and puts out the flame.

Top of Page F Index
Fairy Lamp -- Generally a candle or night lamp with a glass base and domed shade the burns a stubby (votive-type) candle. Range from plain to ornate art glass types.
Feeder Tube -- On a Student or Argand lamp, the structural horizontal tube through which the fuel passes from the fount/tank to the burner.
Figural Stem -- A classification of a composite lamp which has a stem that is molded, carved or cast in relief that depicts a person, animal or object, or combination of elements.
Filler or Feeder Cap -- A removable cover (usually threaded) that allows fuel to be added to the fount without removing the burner.
Finger Lamp -- A lamp made with a loop that allows it to be carried by inserting the index finger through the loop to support the lamp. Can have a flat base, or a footed (raised) base.
Fire Polished -- Reheating an object to remove mold marks and marks left by tools; melting the surface and eliminated superficial irregularity or dullness.
Fitter -- Generally the lower rim (or lip) of a chimney, globe or shade that that fits into a metal ring, burner or holder. A hall lamp shade, for example, would have a fitter on both ends.
Flake -- A thin, shallow chip, 1/16" or smaller in thickness.
Flame Spreader -- In a center draft or argand burner, the apparatus that directs airflow into the center of the flame and deflects the flame outward and upward, thus producing a larger, brighter flame.
Flea-Bite -- An extremely small chip, generally 1/16" or smaller in size, roughly the size of a pin head. Sometimes called a "chigger-bite."
Folded (or Rolled) Rim (or Edge) -- Literally, the folding over of the glass onto itself to create a stronger edge. Commonly found on lamp shade tops.
Fount or Font -- The reservoir or tank that holds the fuel in a lamp. Can be made of metal or glass; fixed or removable.

Top of Page G Index
Gallery -- Refers to the circular metal ring on the top of a burner that accepts the chimney.
Gauffer -- The act of crimping or fluting, such as a chimney top or lamp shade. Can be hand formed or formed with the use of tools.
Gimbal Lamp -- Lamps mounted in double trunnions, or gimbals, with a weighted base that allows it to hang vertically despite movement. Often used on ships and trains.
Globe -- A term often used to describe a lamp shade, particularly a ball shade. Also to describe the lamp glass used in a lantern.
Gone With The Wind Lamp -- Generally a vase or parlor lamp with a removable fount and matching painted or embossed decoration on both the lamp base and shade.

Top of Page H Index
Hall Lamp -- Generally a pull-down lamp with a decorative glass shade, used to illuminate halls and stairways during the night for safety. Not used for general lighting as they do not give a very bright light.
Hand Lamp -- Generally another name for a finger lamp where the fount forms the base of the lamp. Designed to be carried by hand from one place to another. Made of metal or glass.
Hanging Lamp -- Any lamp designed to be suspended from the ceiling.
Haze -- A faint cloudiness of the glass, inside or out, that can be seen upon close inspection.
Harp -- In a hanging lamp, the frame that holds the fount and often supports the shade. Can be heavy wire, cast iron, or brass.
Heat Check -- A crack that is caused, in the case of lamps, when stress is created in the body of the object when the handle is applied. This occurs when the body of the lamp is cooler than the gather of glass used to form the handle or finger ring. If the stress inherent in the object is not relieved through proper annealing, a crack, or heat check, can occur as the item cools.
Hot Blast -- A lantern design whereby some of the hot 'exhaust' air was recirculated down the side tubes and mixed with fresh air and fed to the burner. This was an improvement over the dead-flame configuration.

Top of Page I Index
Insect Screen -- Any perforated metal or wire mesh accessory placed on the top of a lamp chimney to prevent insects and other debris from falling into the burner.

Top of Page J Index
Jeweled -- Any lamp or component part (such as a hanging lamp frame) that is adorned with cut or faceted colored glass cabochons.

Top of Page K - L Index
Ladder Chain -- A type of chain commonly used on hanging lamps characterized by links that are configured into the shape of a ladder. Sometimes solid brass, but most often made of brass-plated steel for strength.
Lantern -- A lighting device, commonly used outdoors, that utilizes a globe to protect the flame from wind and the elements. Most often carried from place to place, thus of fairly rugged construction.
Leveler -- A device used on a hanging lamp to keep the lamp hanging level. Often a spreader that pivots in the center.
Lip -- Commonly the flanged area of a chimney or lamp shade used to secure it to the burner or shade holder, respectively.

Top of Page M Index
Mantle -- A specially made 'tube' or cone of treated material that produces an incandescent glow when heated by a kerosene or gas flame.
Marked -- Referring to an item that contains any manufacturer's mark, logo, hallmark, patent information, etc. Could be either molded in the glass or embossed on the metal.
Mechanical Lamp -- Any lamp characterized by a key-wound, clockwork driven mechanism to "fan" the flame. The fans create a sufficient draft that these lamps are designed to burn without chimneys.
Miniature Lamp -- A diminutive kerosene lamp often used as a night light or in a child's room. Some thought to be used also as salesman's samples as they are smaller replicas of larger lamps. Range from simple lamps to ornate art glass varieties.
Mold Blown Glass -- Glass that is formed by being blown into a shape or pattern mold, not free-formed.
Mold Marks -- Seam lines that remain on the body of the glass after it is removed from the mold.
Motor -- See ceiling extension above.

Top of Page N Index
Night Lamp or Night Light -- A small kerosene lamp designed to be used at night. See also Miniature Lamp.

Top of Page O Index
Oil Guard -- A term associated with Lomax (and similar) lamps that employs an lipped outer rim to catch spilled kerosene. Also referred to as a "spill-guard" lamp.

Top of Page P Index
Patent Dated -- Any information on an object that contains actual patent dates, patent numbers, or other patent information; or information that can be associated with known patents or dates.
Pearl Top -- A rim treatment of a lamp chimney characterized by a ring of beads that encircle the top of the chimney. Usually machine made as the beads are of a uniform size.
Peg Lamp -- In general, a lamp fount designed to use a candlestick as its base. They have a small "peg" resembling the base of a candle and are merely inserted into a candle holder for use.
Perforations -- A series of holes that are stamped or drilled in the burner components to promote air flow.
Petal Top -- A rim treatment of a lamp chimney characterized by hand-made gauffering in a shape resembling the petals of a flower. Petals can vary greatly in size, some are small and others are quite large. Since the petals are formed by hand, the size and shape may vary slightly on the same chimney.
Piano Lamp -- A tall, adjustable-height floor lamp, commonly with a removable center draft fount and decorative ball shade. Generally quite ornate and often part of a marble-top table.
Pickwick -- A small tool used to manipulate or adjust the wick in whale oil and burning fluid lamps. Commonly a metal pin held in a decorative handle of turned or carved wood, ivory or bone.
Pie Crust -- A rim treatment of a lamp chimney characterized by either hand- or machine made crimping along a scalloped edge profile. The design is repetitive from one scallop to the next. Some pie crust chimneys are crudely made, while others are very finely crafted.
Pontil - Polished -- The now-finished area where the glass object was attached to the pontil rod. The rough area is ground and polished, leaving a smooth circular depression.
Pontil - Rough -- The rough, unfinished spot that remains after a glass object is snapped or 'broken' off the pontil rod.
Pot Stone -- The presence of unmelted grains of sand, or other impurities, that are common in early glass. They are usually off-white in color and range greatly in size. Often they can be felt. There may be small cracks radiating from the pot stone caused by temperature differences during the cooling process.
Pressed Glass -- Glassware formed by placing a blob of molten glass in a metal mold, then pressing it with a metal plunger to form the inside shape. The resulting piece, termed "mold-pressed," has an interior form independent of the exterior, in contrast to mold-blown glass, whose interior corresponds to the outer form.
Prisms -- Dangling glass pendants used to embellish a lamp. Often of high quality glass, cut and faceted, to reflect and refract the light. Found on many hanging library/parlor lamps, on girandoles, and overlay lamps, to name a few.
Prism Ring -- A decorative metal ring draped over the shoulder (and collar) of the lamp fount to hold prisms. Common on fancy, cut overlay lamps. Also, the decorative metal ring on a hanging lamp between the canopy and the shade.
Prong -- A flat wick burner type that employs upward facing metal "fingers" that secure or hold the chimney on the burner. Specifically, the metal or wire "fingers" on any burner that hold the chimney in place.
Pull-Down -- Any hanging or suspended lamp that is designed to be raised and lowered by grasping a finial and pulling it downward. The mechanism can be a ceiling extension or series of pulleys and weights.

Top of Page Q - R Index
Reducer -- A threaded metal ring that reduces the opening of the lamp collar to the next smaller size.
Reflector -- Any mirrored surface, often blown mercury glass, or concaved metal surface designed to increase light output by reflection.

Top of Page S Index
Scratch -- Significant abrasions with measurable depth. If you scraped your fingernail over a scratch, you could feel it.
Scuffing -- Light rub marks or abrasions with no appreciable depth.
Set Screw -- A small, gnurled screw that is finger-tightened to secure a shade or chimney into it's holder.
Shade -- A metal, glass, or fabric element designed to diffuse and direct the light produced by the flame. Can be both functional and decorative.
Shade Ring -- A circular ring attached to a lamp or burner which holds the lamp shade. The shade may be attached with set screws, or merely sit in the ring.
Sinumbra -- An improvement of the astral lamp. Characterized by a ring or doughnut shaped fount designed to cast more light downward and minimize the shadow caused by large, centrally located founts. These lamps are relatively tall compared to their width to maximize light output.
Skater's Lantern -- A small lantern used as a night light and often depicted as being used by skaters at night as the circled an icy pond.
Sliver -- A long, narrow flake.
Smoke Bell -- Any domed device of metal or glass that is suspended above a lamp, particularly above the chimney, to reduce smoke and soot build up on the lamp fixture or ceiling.
Smoke Shade -- Of similar design and purpose to the smoke bell, but generally much wider. These are most commonly seen in white milk glass.
Spear -- A term used to describe a large, cut class lamp prism, usually with a pointed end.
Split -- A separation of the metal along a seam due to stress, fatigue, or other outside forces.
Spider -- Another name for a tripod, or lamp shade holder.
Spreader or Spanner -- A decorative metal element on a hanging lamp designed to keep the chains held apart and from twisting. Often the smoke bell is attached to some type of spanner or leveler.
Staining -- Cloudiness or other discoloration of the glass that can easily be seen. More severe than haze.
Stand Lamp -- Generally, any lamp designed to be placed (on furniture) for illumination. Usually an intermediate size lamp which could be carried from place to place if needed, by grabbing ahold of the stem.
Stem -- The portion of the lamp between the fount and the base. Can be one piece or made up of multiple pieces.
Stop Balls -- Any plain or decorative metal balls (usually hollow) affixed to the chains of a ceiling extension which limit the amount of chain that can be retracted back into the mechanism. Also found on hanging lamps with counter-weights used to adjust their height.
Store Lamp -- Commonly refers to a lamp used by merchants to illuminate their shops. A hanging lamp with a large (mammoth) fount and often a slanted tin shade for maximum light reflection.
Straw Mark -- A line or fold often found on the surface of a molded glass object.
Striae -- Small threads of glass molded into the surface of an article.
Stress or Age Crack -- A fracture resulting from the aging of the metal. Common with thin stamped or pressed brass objects such as lamp collars and brass oil founts.
Student Lamp -- Designed to eliminate undershadow and improve the downward light, student lamps are designed around a center post balanced by the fount on one side and the burner/shade on the other. Come in both single & double varieties.
Suspended Lamp -- Any lamp designed to hang from the ceiling. Often placed to illuminate the area under the lamp, such as a table or sitting area.

Top of Page T Index
Tripod -- A three-arm wire lamp shade holder, sometimes encircled by a ring-shaped channel to enclose the shade fitter.
Trim Ring -- A decorative brass ring used to protect the tops of ball shades on GWTW and other lamps. Also, any decorative ring used to embellish the top of a lamp base with a drop-in fount.
Thumb Wheel -- The knob on the burner that is used (turned) to adjust the height of the wick.

Top of Page U - V Index
Vapor Vent -- A means of preventing pressure from building up in the fount by allowing it to vent through the burner by way of a small tube.

Top of Page W - X - Y - Z Index
Wall Plate -- Refers to the mounting plate that attaches to the wall to hold a bracket lamp.
Wheel Engraving -- A process of decorating the surface of glass by the grinding action of a wheel. An abrasive in a grease or slurry is applied to a wheel, as the engraver holds the object against the underside of the rotating wheel. See Copper-wheel engraving
Wick -- That which carries liquid fuel from the fount to the burner for combustion. Usually of cotton or similar material. Flat, round, braided, etc.
Wick Trimming -- The act of cutting or shaping the wick to produce a better shaped flame (and to remove carbon build-up), thus producing better light. Often done with specially made scissors. Also refers to a special adaptation of many burners which allows the gallery to be raised to expose the wick without removing the chimney and in some cases, the shade. The burner can also be lighted in this fashion.
Wick Tube -- The part of the burner into which the wick is inserted and adjusted. Supports the wick and prevents the flame from migrating down into the fuel source.
Wick Wheel -- The toothed "gear" or "sprocket" that engages the wick and allows it to be adjusted by turning the thumb wheel.
Winder -- See ceiling extension above.

INDEX

A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Glossary updated January 8, 2003