#444. Spectator.—N. spectator, beholder, observer, looker-on, onlooker, witness, eyewitness, bystander, passer by; sightseer; rubberneck * [U. S.].
spy; sentinel &c. (warning) 668.
V. witness, behold &c. (see) 441; look on &c. (be present) 186; gawk, rubber *, rubberneck *[U.S.].

#445. Optical Instruments.—N. optical instruments; lens, meniscus, magnifier, sunglass, magnifying glass, hand lens; microscope, megascope[obs3], tienoscope[obs3]. spectacles, specs [coll.],glasses, barnacles, goggles, eyeglass, pince-nez, monocle, reading glasses, bifocals; contact lenses, soft lenses, hard lenses; sunglasses, shades[coll.]. periscopic lens[obs3]; telescope, glass, lorgnette; spyglass, opera glass, binocular, binoculars, field glass; burning glass, convex lens, concave lens, convexo-concave lens[obs3], coated lens, multiple lens, compound lens, lens system, telephoto lens, wide-angle lens, fish-eye lens, zoom lens; optical bench. astronomical telescope, reflecting telescope, reflector, refracting telescope, refractor, Newtonian telescope, folded-path telescope, finder telescope, chromatoscope; X-ray telescope; radiotelescope, phased-array telescope, Very Large Array radiotelescope; ultraviolet telescope; infrared telescope; star spectroscope; space telescope. [telescope mounts] altazimuth mount, equatorial mount. refractometer, circular dichroism spectrometer. interferometer. phase-contrast microscope, fluorescence microscope, dissecting microscope; electron microscope, transmission electron microscope; scanning electron microscope, SEM; scanning tunneling electron microscope. [microscope components] objective lens, eyepiece, barrel, platform, focusing knob; slide, slide glass, cover glass, counting chamber; illuminator, light source, polarizer, [component parts of telescopes] reticle, cross-hairs. light pipe, fiber optics mirror, reflector, speculum; looking-glass, pier-glass, cheval-glass, rear-view mirror, hand mirror, one-way mirror, magnifying mirror. [room with distorting mirrors] fun house. prism, diffraction grating; beam splitter, half-wave plate, quarter- wave plate. camera lucida[Lat], camera obscura[Lat]; magic lantern &c. (show) 448; stereopticon; chromatrope[obs3], thaumatrope[obs3]; stereoscope, pseudoscope[obs3], polyscope[obs3], kaleidoscope. photometer, eriometer[obs3], actinometer[obs3], lucimeter[obs3], radiometer; ligth detector, photodiode, photomultiplier, photodiode array, photocell. X-ray diffractometer, goniometer. spectrometer, monochrometer, UV spectrometer, visible spectrometer, Infrared spectrometer, Fourier transform infrared spectrometer, recording spectrometer; densitometer, scanning densitometer, two-dimensional densitometer. abdominoscope[obs3], gastroscope[Med], helioscope[obs3], polariscope[obs3], polemoscope[obs3], spectroscope. abdominoscopy[obs3]; gastroscopy[Med]; microscopy, microscopist.

#446. Visibility.—N. visibility, perceptibility; conspicuousness, distinctness &c. adj.; conspicuity[obs3], conspicuousness; appearance &c. 448; bassetting[obs3]; exposure; manifestation &c. 525; ocular proof, ocular evidence, ocular demonstration; field of view &c. (vision) 441; periscopism[obs3]. V. be become visible &c. adj.; appear, open to the view; meet the eye, catch the eye; basset; present itself, show manifest itself, produce itself, discover itself, reveal itself, expose itself, betray itself; stand forth, stand out; materialize; show; arise; peep out, peer out, crop out; start up, spring up, show up, turn up, crop up; glimmer, loom; glare; burst forth; burst upon the view, burst upon the sight; heave in sight; come in sight, come into view, come out, come forth, come forward; see the light of day; break through the clouds; make its appearance, show its face, appear to one's eyes, come upon the stage, float before the eyes, speak for itself &c. (manifest) 525; attract the attention &c. 457; reappear; live in a glass house. expose to view &c. 525. Adj. visible, perceptible, perceivable, discernible, apparent; in view, in full view, in sight; exposed to view, en evidence; unclouded, unobscured[obs3], in the foreground. obvious &c. (manifest) 525; plain, clear, distinct, definite; well defined, well marked; in focus; recognizable, palpable, autoptical[obs3]; glaring, staring, conspicuous; stereoscopic; in bold, in strong relief. periscopic[obs3], panoramic. before one's eyes, under one's eyes; before one, vue d'oeil[Fr], in one's eye, oculis subjecta fidelibus[Lat]. Adv. visibly &c. adj.; in sight of; before one's eyes &c. adj.; veluti in speculum[Lat].

#447. Invisibility.—N. invisibility, invisibleness, nonappearance,
imperceptibility; indistinctness &c. adj.; mystery, delitescence[obs3].
concealment &c. 528; latency &c. 526.
V. be invisible &c. adj.; be hidden &c. (hide) 528; lurk &c. (lie
hidden) 526; escape notice.
render invisible &c. adj.; conceal &c. 528; put out of sight.
not see &c. (be blind) 442; lose sight of.
Adj. invisible, imperceptible; undiscernible[obs3], indiscernible;
unapparent, non-apparent; out of sight, not in sight; a perte de
vue[French]; behind the scenes, behind the curtain; viewless, sightless;
inconspicuous, unconspicuous[obs3]; unseen &c. (see see &c. 441); covert
&c. (latent) 526; eclipsed, under an eclipse.
dim &c. (faint) 422; mysterious, dark, obscure, confused; indistinct,
indistinguishable; shadowy, indefinite, undefined; ill-defined, ill-marked;
blurred, fuzzy, out of focus; misty &c. (opaque) 426; delitescent[obs3].
hidden, obscured, covered, veiled (concealed) 528.
Phr. "full many a flower is born to blush unseen" [Gray].

#448. Appearance.—N. appearance, phenomenon, sight, spectacle, show, premonstration|, scene, species, view, coup d'oeil[Fr]; lookout, outlook, prospect, vista, perspective, bird's-eye view, scenery, landscape, picture, tableau; display, exposure, mise en scene[Fr]; rising of the curtain. phantasm, phantom &c. (fallacy of vision) 443. pageant, spectacle; peep-show, raree-show, gallanty-show; ombres chinoises[Sp]; magic lantern, phantasmagoria, dissolving views; biograph[obs3], cinematograph, moving pictures; panorama, diorama, cosmorama[obs3], georama[obs3]; coup de theatre, jeu de theatre[Fr]; pageantry &c. (ostentation) 882; insignia &c. (indication) 550. aspect, angle, phase, phasis[obs3], seeming; shape &c. (form) 240; guise, look, complexion, color, image, mien, air, cast, carriage, port, demeanor; presence, expression, first blush, face of the thing; point of view, light. lineament feature trait lines; outline, outside; contour, face, countenance, physiognomy, visage, phiz[obs3],. cast of countenance, profile, tournure[obs3], cut of one's jib, metoposcopy[obs3]; outside &c. 220. V. appear; be visible, become visible &c. 446; seem, look, show; present the appearance of, wear the appearance of, carry the appearance of, have the appearance of, bear the appearance of, exhibit the appearance of, take the appearance of, take on the appearance of, assume the appearance, present the semblance of, wear the semblance of, carry the semblance of, have the semblance of, bear the semblance of, exhibit the semblance of, take the semblance of, take on the semblance of, assume the semblance of; look like; cut a figure, figure; present to the view; show &c. (make manifest) 525. Adj. apparent, seeming, ostensible; on view. Adv. apparently; to all seeming, to all appearance; ostensibly, seemingly, as it seems, on the face of it, prima facie [Lat]; at the first blush, at first sight; in the eyes of; to the eye. Phr. editio princeps [Lat].

#449. Disappearance.—N. disappearance, evanescence, eclipse,
occultation.
departure &c. 293; exit; vanishing point; dissolving views.
V. disappear, vanish, dissolve, fade, melt away, pass, go,
avaunt[obs3], evaporate, vaporize; be gone &c. adj.; leave no trace, leave
"not a rack behind" [Tempest]; go off the stage &c. (depart) 293; suffer
an eclipse, undergo an eclipse; retire from sight; be lost to view, pass
out of sight.
lose sight of.
efface &c. 552.
Adj. disappearing &c. v.; evanescent; missing, lost; lost to sight,
lost to view; gone.
Int. vanish! disappear! avaunt[obs3]! get lost! get out of here &c.
(ejection) 297.

CLASS IV
WORDS RELATING TO THE INTELLECTUAL FACULTIES

DIVISION (I) FORMATION OF IDEAS

SECTION I. OPERATIONS OF INTELLECT IN GENERAL

#450. Intellect.—N. intellect, mind, understanding, reason, thinking principle; rationality; cogitative faculties, cognitive faculties, discursive faculties, reasoning faculties, intellectual faculties; faculties, senses, consciousness, observation, percipience, intelligence, intellection, intuition, association of ideas, instinct, conception, judgment, wits, parts, capacity, intellectuality, genius; brains, cognitive powers, intellectual powers; wit &c. 498; ability &c. (skill) 698; wisdom &c. 498; Vernunft[Ger], Verstand[Ger]. soul, spirit, ghost, inner man, heart, breast, bosom, penetralia mentis[Lat], divina particula aurae[Lat], heart's core; the Absolute, psyche, subliminal consciousness, supreme principle. brain, organ of thought, seat of thought; sensorium[obs3], sensory; head, headpiece; pate, noddle[obs3], noggin, skull, scull, pericranium[Med], cerebrum, cranium, brainpan[obs3], sconce, upper story. [in computers] central processing unit, CPU; arithmetic and logical unit, ALU. [Science of mind] metaphysics; psychics, psychology; ideology; mental philosophy, moral philosophy; philosophy of the mind; pneumatology[obs3], phrenology; craniology[Med], cranioscopy[Med]. ideality, idealism; transcendentalism, spiritualism; immateriality &c. 317; universal concept, universal conception. metaphysician, psychologist &c. V. note, notice, mark; take notice of, take cognizance of be aware of, be conscious of; realize; appreciate; ruminate &c. (think) 451; fancy &c. (imagine) 515. Adj. intellectual[Relating to intellect], mental, rational, subjective, metaphysical, nooscopic[obs3], spiritual; ghostly; psychical[obs3], psychological; cerebral; animastic[obs3]; brainy; hyperphysical[obs3], superphysical[obs3]; subconscious, subliminal. immaterial &c. 317; endowed with reason. Adv. in petto. Phr. ens rationis [Lat]; frons est animi janua [Lat][Cicero]; locos y ninos dicen la verdad [Sp]; mens sola loco non exulat [Lat][Ovid]; "my mind is my kingdom" [Campbell]; "stern men with empires in their brains" [Lowell]; "the mind, the music breathing from her face" [Byron]; "thou living ray of intellectual Fire" [Falconer].