The Readable Dictionary/1 Light

From Wikisource
Jump to navigation Jump to search

THE TOPICAL LEXICON.


OF LIGHT.

1. Terms significant of the various modifications of Light.

LIGHT is the agent which renders objects visible.

Light, in a figurative sense, is the information which enables us to apprehend the true nature and relations of things.

Note 1.—There are two theories in regard to the nature of light. The one theory supposes light to be a material fluid, emanating in minute particles from luminous bodies. According to the other theory, the sensation of light is produced by the undulations of a subtle ether acting on the organs of sight, in a manner analogous to that in which the undulations of the air, acting on the organs of hearing, produce the sensation of sound. The latter of these theories is generally received by scientific men of the present day.

Note 2.—Light is propagated through space in right lines, at the rate of 192,000 miles per second.

To Shine is either to emit inherent light, as the sun; or to reflect borrowed light, as the moon.

A Sheen is a reflected shining.

And the sheen of their spears was like stars on the sea,
When the blue wave rolls nightly on deep Galilee.—Byron.

Bright, either emitting or reflecting light freely. The sun is bright, as is likewise the piece of polished steel that reflects his brightness.

Dim, either emitting or reflecting a faint light.

The stars shall die, the sun grow dim with age.—Addison.

How is the gold become dim!—Lam. iv.

Dull, deficient either in native or borrowed brightness. A lamp that needs trimming gives a dull light, A key that is not used becomes dull.

To Flicker is to shine with a feeble and unsteady light, like the flame of an expiring lamp.

To Twinkle is to shine with a small intermitting light.

Note.—Twinkle is a modification of winkle, which is a diminutive and frequentative of wink. When, therefore, we say that the stars twinkle, we compare them to little eyes that open and shut with great rapidity.

To Sparkle is to shine with a resemblance of sparks. A collection of small diamonds sparkles. Spangles of frost sparkle in the sunlight.

A Spangle is, 1. A small plate or boss of shining metal. 2. Any little thing that is very bright and sparkling.

To Spangle, or to Bespangle, is to adorn with spangles.

The spacious firmament on high,
With all the blue, ethereal sky,
And spangled heavens, a shining frame,
Their great Original proclaim.—Addison.

To Glimmer is to shine with a faint and tremulous light. Dying embers glimmer on the hearth. The early dawn glimmers in the east.

To Gleam is to shoot forth small streams of light.

The meek-eyed morn appears, mother of dews, At first faint gleaming in the dappled east.—Thomson.

Figuratively, we speak of a gleam of hope.

To Glitter is to shine with an unsteady and irregular emission or reflection of light. The stars glitter, The diamond on a lady's ring glitters.

To Glister is to shine with a keen and sparkling light.

Pleasant the sun,
When first on this delightful land he spreads
His orient beams on herb, tree, fruit, and flower,
Glistering with dew.—Milton.

Gloss is the reflection of light from a smooth surface; as, the gloss of silk.

To Glisten is to shine with a reflection of light from a glossy surface. A well-polished boot glistens. A tear-drop glistens in the eye.

To Glow is to shine with heat. A bar of iron glows when it is first withdrawn from the furnace of a smith's forge.

To Glow also signifies to shine without heat. Certain insects glow in the dark.

To Flare is to shine with a wavering light, as the flame of a lamp when it is agitated by the wind.

To Flash is to send forth a sudden and momentary light.

To Coruscate is to send forth flashes of light. Lightning coruscates.

To Blaze is to shine with a broad and flame-like light.

To Dazzle is to overpower the eye with light. We are dazzled by the brightness of the sun.

To Glare is to shine with a strong and offensive light.

Here in a grotto, sheltered close from air,
And screened in shades from day's detested glare,
She sighs forever.—Pope.

To Glare is also to look with fierce, piercing eyes.

Note.—The glaring of the eyes depends upon a vivid reflection of light.

To Beam is to send forth a strong and steady light; as, the beaming sun.

A Glimpse is, 1. A weak, faint light; as, scarce a glimpse of light.—Milton.

2. A flash of light.

Swift as the lightning's glimpse they ran.—Milton.

3. A transient luster.

One glimpse of glory to thy issue give.—Dryden.

4. A short, transitory view.

Briller, to sparkle (Fr.) Hence, Brilliant, sparkling; as a brilliant gem.

Lux, light; and Luceo, to shine (L.) Hence,

Lucid, bright; as, the lucid orbs of heaven. Fig, 1. Clear and easily understood; as a lucid arrangement.

2. Illuminated by the light of reason. Lunatics sometimes enjoy lucid intervals.

Elucidate, lit., to place in a clear light. Hence, to render intelligible; as, to elucidate an obscure passage.

Translucent, transmitting light, but not transparent. A cup of Chinaware, or a vase of alabaster is translucent, (trans, through.)

Lucifer, light-bearing; as, lucifer matches. (L. fero, to bear.)

Lucifer, the Morning Star; so called because this star precedes the sun, and bears, or brings in, the light of day.

Lucifer, Satan.

Note.—In Isaiah xiv, 11, the king of Babylon is thus addressed: "How art thou fallen from Heaven, O Lucifer, Son of the morning!" Tertullian and Gregory the Great understood this of the fall of Satan, and from this circumstance the name Lucifer has since been applied to Satan.—Robinson's Calmet.

Lumen, light (L.) Hence,

Luminous, emitting light; as a luminous body.

Luminary, a body that emits light.

Illuminate, to enlighten, (or to cast light upon.) (il for in, upon.)

Illume and Illumine, poetic forms of illuminate.

Relume, or Relumine, to light or kindle again; as to relume a dying lamp, (re, again.)

Note.—Relume and Relumine are also poetical terms.

Splendeo, to shine with a strong and vivid light. (L.) Hence,

Splendid, very bright, either literally or figuratively; as a splendid luminary; a splendid equipage; a splendid achievement.

Splendor, great brightness, both lit. and fig.; as, the splendor of the sun; the splendor of noble deeds.

Resplendent, shining with a brilliant reflection of light, (re, back.)

Resplendence or Resplendency, a brilliant reflection of light.

Fulgeo, to shine with great brightness. (L.) Hence,

Refulgent, reflecting light with great brilliancy, (re, back.)

Effulgent, sending forth a flood of light; as the effulgent orb of day. (ef for ex, forth.)

Incandesco, to become white. (L.) Hence,

Incandescent, glowing with a white heat. When a bar of iron is heated it first becomes red, and, as the heat increases, it becomes incandescent.

Luster, brightness; as, the luster of the sun; the luster of silk; the luster of a great name.

Lustrous, 1. Bright, Good sparks and lustrous.Shakspeare. 2. Glossy; as, lustrous locks.

Illustrate, lit, to add luster or brightness. Hence, to make clear or intelligible by means of comments, examples, or pictures. (Il for in, upon.)

Illustrious, brightened with the splendor of high rank, or of great and noble achievements; as, an illustrious prince.

Radius, the spoke of a wheel. (L.) Hence,

Ray, (contraction of radius,) a single line of light; because rays diverge from a luminous point like spokes from the hub of a wheel.

Radiate, to send forth rays.

Radiation, the act of sending forth rays.

Radiant, sending forth copious rays; as, the radiant sun.

Radiance, or Radiancy, vivid brightness, caused by radiation from a copious source of light.

Irradiate, to overspread an object or scene with rays of light, [ir for in, upon.)

ΦΩΣ [PHOS], light. (Gr.) Hence,

Phosphor, the Morning Star. (Gr. φερω [phero], to bear.)

Phosphorus, a chemical element, so called from the readiness with which it is rendered luminous by friction.

Phosphorescent, shining with inherent light, without sensible heat. Decayed wood is sometimes phosphorescent.

Photography, the art of forming pictures by means of light. (Gr., γραφω [grapho], to draw, or delineate.)

Photometer, an instrument for measuring the intensity of light. (Gr., μετρεω [metreo], to measure.)

To Wane, is to decrease in brightness. The moon wanes nightly after the full.

To Tarnish, is to diminish the luster, as that of a piece of burnished silver.

Note.—Metals tarnish by oxydation. See Art. Chemistry.

A Beam is a body of parallel rays.

A Pencil is a body of rays that either converge or diverge.

A Focus is the common point to which rays converge, or from which they diverge.

A Rainbow is an arch of variously colored light, formed by the action of falling drops of rain upon the sun's rays.

A Halo is a luminous circle which sometimes surrounds the sun or the moon.

Note.—The halo is supposed to be caused by the action of small crystals of frozen vapor upon the rays of the sun or moon.

A Corona is a small luminous circle surrounding the sun or the moon.

Note.—The corona is caused by the action of small particles of watery vapor upon the light of the sun or moon. (L., corona, a crown.)

A Glory is a halo surrounding the head of the Savior in pictures.

A Parhelion, or Mock-sun, is a luminous appearance resembling the sun, which is sometimes seen on the circumference of a solar halo.

Note.—Two parhelia are usually visible at the same time, horizontally opposite to each other. (Gr. παρα [para], near; and ήλιος [helios], the sun.

Lightning consists in the evolution of light by the rapid passage of a body of the electric fluid through the air.

A Meteor is a luminous body either floating in, or flying rapidly through the air, or above it. (Gr μετεωρος [meteoros], elevated.

Shooting Stars, Bolides, or Fire-balls, are luminous bodies which suddenly appear in the sky, usually at a great hight above the earth, and shoot through the heavens with immense velocity. (Bol'-i-des, pl. of βολις [bolis], a dart.)

Note.—Shooting Stars sometimes consist of small bodies of solid matter moving through space, and approaching so near the earth as to become visible. That some shooting stars are solid, is known from the fact, that they sometimes burst in the atmosphere with a loud explosion, when either a portion or the whole of the meteor falls to the earth in the form of a shower of stones, called meteoric stones.

At other times, a shooting star or fireball consists of a body of light, vapory matter precipitated from the regions of space into the atmosphere, where it is ignited by friction, and is consumed or dissipated before it can reach the ground. The grandest display of meteors of this kind on record, was witnessed in North America, on the morning of the 13th of November, 1833. The appearance presented was that of an uninterrupted shower of fire, which continued for several hours. These meteors are supposed to have had their origin in a small comet or planetoid, which happened at that time to come within a few thousand miles of the earth.

A third class of fireballs have their origin in the atmosphere, and are either electrical, or consist of collections of phosphorescent matter.

The Will-o'-the-Wisp, Will-with-a-Wisp or Will-a-Wisp, is a luminous vapor seen at night in marshes and graveyards.

Note.—This meteor consists of phosphorescent matter evolved from decaying animal and vegetable substances. (Wisp, a small bundle of lighted straw, and Will, the name of the fellow that carries it.

Jack-with-a-Lantern, is the brother of Will-o'-the-Wisp.

Note.—Jack and Will are both naughty boys who delight in frightening the ignorant, and in leading bewildered nightfarers a long chase over bogs and ditches.

Will-a-Wisp misleads nightfaring clowns
O'er hills and sinking bogs.—Gay.

Ignis Fatuus (plural, ignes fatui,) is a Latin designation of the meteor called the Will-o'-the-Wisp. (Ignis, fire; and fatuus, unreal.)

Twilight is the faint light which is reflected upon the earth before sunrise and after sunset. (Twi., doubtful.)

Dawn is the morning twilight. Fig., the beginning; as, the dawn of reason in the mind of a child.

An Aurora or Polar Light, is a luminous appearance of the sky at night, commonly seen in the direction of the pole that is nearest to the observer, and resembling the illumination of the east which precedes the rising of the sun. (L., aurora, the dawn)

Auroral, pertaining to the polar lights.

Aurora Borealis, the north polar lights. (L., borealis, northern.)

Aurora Australis, the south polar lights. (L., australis, southern.)

Northern Lights, the common English name of the northern aurora.

Note.—Auroral light is supposed to be caused by the action of electricity.

The Zodiacal Light is a faint, nebulous (cloudy) aurora which accompanies the sun. It has a flat lenticular (bean-shaped) form, with the sun in the middle, and is visible shortly before sunrise and soon after sunset, extending obliquely upward.

Note.—Sir John Herschell conjectures that this light consists of the same kind of matter that constitutes the tail of comets. (Called zodiacal, because situated in the zodiac. See Art. Astronomy.)


2. Artificial Luminaries.

A Candle is a cylinder of tallow or wax, with a portion of cotton thread, called the wick, running lengthwise through the middle.

A Lamp is a small vessel in which oil or some other liquid is burned for the production of light.

A Taper is a small wax candle.

A Rushlight is a very small and feeble light, produced by burning a rush which has been dipped in tallow.

Note.—The rushlight is chiefly used in sick chambers.

A Flambeau is a luminary having usually several branches, which consist of very large wicks covered with wax or tallow.

Note.—Flambeaus are used in the streets at night, at illuminations, and in processions. (Fr., flamme, a flame; and beau, beautiful.)

A Torch is a large blazing light borne in the hand.

A Candlestick is a utensil for holding a candle.

A Chandelier is a frame with branches for lights.

3. Relations of Bodies to Light.

Transparent bodies permit light to pass so freely, that objects beyond may be plainly seen. (L., trans, through; and pareo, to appear.)

Opake bodies are such as do not permit light to pass. A pane of window glass is transparent, but a board is opake.

Opacity (from opake) signifies a want of transparency. Blindness is sometimes caused by an opacity of the lens of the eye.

Opake also signifies not self-luminous. The sun is self-luminous, but the moon is an opake body. (L., opacus, shady.)

Clear. When bodies which are expected to be transparent are free from foreign matters, discolorations, and whatever else may tend to impair their transparency, they are said to be clear, as the air when free from mist, smoke, or dust; and water, when free from impurities.

Pellucid, perfectly transparent. (Pel for per, through; and luceo, to shine.)

Limpid, transparent. (Spoken only of liquids; as, a limpid stream.)

Semi-transparent, imperfectly transparent. (Semi, half.)

Translucent, permitting light to pass, but not so freely that objects beyond can be seen. (L., trans, through; and luceo, to shine.)

Diaphanous, transparent. (Gr., δια [dia] through; and φαινω [phaino], to shine.)

Crystal, resembling in transparency the mineral bodies called crystals; as a crystal fountain.


4. Of Darkness.

DARKNESS is the absence of light. In a figurative sense darkness is the absence of intellectual or spiritual light.

Dusk is a partial darkness. The dusk of the evening is the evening twilight.

Gloom is darkness, either partial or total; as, the gloom of a dense forest; the gloom of midnight.

Gloom, in a fig. sense, as denoting a state of the mind, is an absence of cheerfulness.

Murk is darkness.

Ere twice in murk and occidental damp,
Moist Hesperus hath quenched his sleepy lamp.—Shaks.

Murky, dark.

A murky storm, deep, low'ring o'er our heads,
Hung imminent, that, with imperious gloom,
Opposed itself to Cynthia's silver ray.—Addison.

Obscure, wanting light to such a degree, that objects can not be plainly discerned. Hence, fig. 1. Not easily understood; as, an obscure subject. 2. Not noted; as, an obscure person.

Sombre, gloomy; as, a sombre day. (Sp. sombra, a shade, from L. umbra.)

Shade consists in an absence of light caused by the interposition of an opake body between a surface, or empty space, and the source of light.

A Shadow is a shade with a definite outline delineated on a surface, the outline corresponding in form to the figure of the body which projects the shadow.

Umbra, a shade or shadow. (L.) Hence,

Umbrageous, shady; as, an umbrageous forest.

Umbrella, lit, a little shade. Hence a screen held in the hand as a protection against the sun or rain.

Umbrage. 1. Shade: <poem>

Men, sweltering, run To grots and caves, and the cool umbrage seek Of woven arborets.—Philips.

2. Shadow or appearance. The opinion carries no show of truth nor umbrage of reason on its side.—Woodward.

3. Offense taken at a procedure which we suspect as being designed to operate to our disadvantage.

Note 1.—Until the suspicion becomes a certainty, it is a mere umbra or shade.

Note 2.—Another explanation of the figure implied in the use of the word umbrage, in the sense of offense, is, that the cause of the offense casts a shadow over the mind of the offended party.

The Umbra is the dark spot on the earth's surface in the case of a total eclipse of the sun.

Note.—The diameter of the umbra can not exceed 200 miles, and may vary from that diameter down to nothing.

The Penumbra is the portion of the earth's surface that is partially shaded in the case of a total eclipse of the sun. (L. pene, almost.)

Note.—The diameter of the penumbra may vary slightly, but is usually about 4000 miles.


The Attributes of Darkness.

Darkness seems to be of a black color. The reason of this is, that, according to the theory of colors, blackness is owing to the non-reflection of light from the surfaces of bodies; and consequently, where no light exists to be reflected, nothing but seeming blackness can meet the eye.

When we speak of a deep gloom, we refer to the apparent, color of the gloom, as closely approximating to perfect blackness, deep being an epithet which, when applied to color, denotes intensity.

When we speak of darkness as being profound, we present the idea of local depth, as that of a fathomless pit.

When we speak of darkness as being thick, or gross, we represent it as a dark-colored fluid of great density.

When we speak of the sun's dispelling, dispersing, or scattering darkness, we represent it as something analagous to a fog or mist which is brushed away by the rising breeze.

When we speak of darknes as hovering or brooding over a scene, we represent it under the figure of a huge dark-colored fowl overshadowing the scene with its expanded wings.

Egyptian darkness is a figurative expression, denoting the utter absence of moral illumination among a people. The allusion is to the darkness which, in the time of Moses, covered the land of Egypt for the space of three days.

Cimmerian darkness is such as was represented by the ancients as perpetually involving the region of Cimmeria, (now Crimea.)

Sink and disperse, ye specter doubts that roll Cimmerian darkness on the parting soul. Campbell.