=Acanthodus= (_a-kan-thō´dus_).--Fossil fish, having thorn-like fins.
=Aërodynamics= (_ā-ẽr-ō-di-nam´iks_).--The science which treats of the
air and other gaseous bodies under the action of force, and of their
mechanical effects.
=Aërognosy= (_ā-ẽr-ŏg´nô-sy_̆).--The science which treats of the
properties of the air, and of the part it plays in nature.
=Aërolite= (_ā´ẽr-ô-līt_).--A stone, or metallic mass, which has fallen
to the earth from distant space; a meteorite; a meteoric stone.
=Aërology= (_ā-ẽr-ŏl´ôjy̆_).--That department of physics which treats of
the atmosphere.
=Aerometer= (_ā´ẽr-ŏm´ê-tẽr_).--An instrument for ascertaining the
weight or density of air and gases.
=Ammonites= (_am´mo-nitz_).--Fossil mollusks of spiral form, found in
all strata from the palæozoic to the chalk; very numerous, varying
greatly in size; all now extinct; sometimes called snakestones.
=Anemology= (_ăn-ĕ-mŏl´ô-jy̆_).--The science of the wind.
=Anemometer= (_ăn-ĕ-mŏm´ẽ-tẽr_).--An instrument for measuring the force
and velocity of the wind; a wind gauge.
=Attrition= (_ăt-trĭsh´ŭn_).--The act of rubbing together; friction; the
act of wearing by friction, or by rubbing substances together; abrasion.
=Aurora= (_aw-rō´rȧ_).--The rising light of the morning; the dawn of
day; the redness of the sky just before the sun rises.
=Aurora Borealis= (_bō´rẽ-ā´lĭs_), i. e., northern daybreak; popularly
called northern lights. A luminous meteoric phenomenon, visible only at
night, and supposed to be of electrical origin. This species of light
usually appears in streams, ascending toward the zenith from a dusky
line or bank, a few degrees above the northern horizon. Occasionally the
aurora appears as an arch of light across the heavens from east to west.
Sometimes it assumes a wavy appearance. They assume a variety of colors,
from a pale red or yellow to a deep red or blood color.
The =Aurora Australis= (_aws-trā´lĭs_) is a corresponding phenomenon in
the southern hemisphere, the streams of light ascending in the same
manner from near the southern horizon.
=Barometer= (_bȧ-rŏm´ẽ-tẽr_).--An instrument for determining the weight
or pressure of the atmosphere, and hence for judging of the probable
changes of weather, or for ascertaining the height of any ascent.
=Calamites= (_kal´a-mīts_ or _kal´a-mī´tēz_).--Reed-like plants, found
in coal.
=Carboniferous= (_kär´bŏn-ĭf´ẽr-ŭs_).--Producing or containing carbon or
coal.
=Conglomerate= (_kŏn-glŏm´ẽr-ât_).--Pudding stone, composed of gravel
and pebbles cemented together.
=Corona= (_kô-rō´nȧ_).--A circle, usually colored, seen in peculiar
states of the atmosphere around and close to a luminous body as the sun
or moon.
=Cosmogony= (_kŏs-mŏg´o-ny̆_).--The creation of the world or universe; a
theory or account of such creation.
=Cosmology= (_kŏz-mŏl´ô-jy̆_).--The science of the world or universe; or
a treatise relating to the structure and parts of the system of
creation, the elements of bodies, the modifications of material things,
the laws of motion, and the order and course of nature.
=Crystallography= (_krĭs´tal-lŏg´rȧ-fy̆_).--The science of
crystallization, teaching the system of forms among crystals, their
structure, and their methods of formation.
=Cyclone= (_sī´klōn_).--A violent storm, often of vast extent,
characterized by high winds rotating about a calm center of low
atmospheric pressure. This center moves onward, often with a velocity of
twenty or thirty miles an hour.
=Denudation= (_dĕn´û-dā´shŭn_ or _dē´nū-_).--The laying bare of rocks by
the washing away of the overlying earth, etc.; or the excavation and
removal of them by the action of running water.
=Deposit.=--A body of ore distinct from a ledge; pocket of gravel or pay
dirt.
=Diplacanthus= (_dip-lä-kăn´thus_).--A fish, belonging to Acanthodii,
known only by fossil remains in Old Red Sandstone.
=Drifts.=--Tunnels leading off from the main shaft, or from other
tunnels or levels, through and along the vein.
=Drift Matter.=--Earth, pebbles and bowlders that have been drifted by
water, and deposited over a country while submerged.
=Druse= (_drṳs_).--A cavity in a rock, having its interior surface
studded with crystals and sometimes filled with water.
=Elephas= (_el´e-fas_).--The Latin name for Elephant. The primitive
elephant was what is known as the Mammoth.
=Fata Morgana= (_fä´tȧ môr-gä´nȧ_).--A kind of mirage by which distant
objects appear inverted, distorted, displaced, or multiplied. It is
noticed particularly at the Straits of Messina, between Calabria and
Sicily, Italy.
=Fire-damp.=--An explosive carburetted hydrogen of coal mines.
=Fissures.=--Seams or crevices in rocks formed by volcanic or earthquake
action, and when filled subsequently by metal or metallic ores they
become fissure veins.
=Fog.=--Watery vapor condensed in the lower part of the atmosphere and
disturbing its transparency. It differs from cloud only in being near
the ground, and from mist in not approaching so nearly to fine rain.
=Geography= (_je-ŏg´rȧ-fy̆_).--The science which treats of the world and
its inhabitants; a description of the earth, or a portion of the earth,
including its structure, features, products, political divisions, and
the people by whom it is inhabited.
ASTRONOMICAL, or MATHEMATICAL GEOGRAPHY treats of the earth as a planet,
of its shape, its size, its lines of latitude and longitude, its zones
and the phenomena due to the earth’s diurnal and annual motions.
PHYSICAL GEOGRAPHY or PHYSIOGRAPHY treats of the conformation of the
earth’s surface, of the distribution of land and water, of minerals,
plants, animals, etc., and applies the principles of physics to the
explanation of the diversities of climate, productions, etc.
POLITICAL GEOGRAPHY treats of the different countries into which the
earth is divided with regard to political and social institutions and
conditions.
=Geology= (_jē-ŏl´o-jy̆_).--The science which treats: (a) Of the
structure and mineral constitution of the globe; structural geology. (b)
Of its history as regards rocks, minerals, rivers, valleys, mountains,
climates, life, etc.; historical geology. (c) Of the causes and methods
by which its structure, features, changes, and conditions have been
produced; dynamical geology.
=Goniatites= (_gō-ni-a-tī´tēz_).--Fossil remains of Ammonites, many
species of which are found in Devonian and Carboniferous Limestone.
=Hail= (_hāl_).--Frozen rain, or particles of ice precipitated from the
clouds, where they are formed by the congelation of vapor. The separate
particles are called hailstones.
=Harmattan= (_här-măt´tan_).--A dry, hot wind, prevailing on the
Atlantic coast of Africa, in December, January, and February, blowing
from the interior or Sahara. It is usually accompanied by a haze which
obscures the sun.
=Hoarfrost= (_hōr´frŏst_).--The white particles formed by the
congelation of dew; white frost.
=Hydrography= (_hī-drŏg´rȧ-fy̆_).--The art of measuring and describing
the sea, lakes, rivers, and other waters, with their phenomena.
=Hygrometer= (_hī-grŏm´ê-tẽr_).--An instrument for measuring the degree
of moisture of the atmosphere.
=Ignis fatuus= (_ĭg´-nĭs făt´ûŭs_).--A phosphorescent light that
appears, in the night, over marshy grounds, supposed to be occasioned by
the decomposition of animal or vegetable substances, or by some
inflammable gas,--popularly called also Will-with-the-wisp, or
Will-o’-the-wisp, and Jack-with-a-lantern, or Jack-o’-lantern.
=Ichthyosaurus= (_ĭk-thē-ō-saw´rus_).--A large marine reptile, known
only by fossil vertebræ and other bones, found in oolite rocks.
=Labyrinthodon= (_lab-i-rin´thō-don_), or Mastodon. A large animal,
belonging to Amphibia, remains of which are found in Upper Trias rocks
and strata.
=Lepidodendron= (_lep-i-dō-den´dron_).--Coal-plants, belonging to the
Lycopods, of which very many remains are found in coal.
=Lepidosteus= (_lep-i-dŏs´te-us_).--Bony-pike fish, the fossil remains
of which are found in rocks and earth strata.
=Lightning= (_līt´nĭng_).--A discharge of atmospheric electricity,
accompanied by a vivid flash of light, commonly from one cloud to
another, sometimes from a cloud to the earth. The sound produced by the
electricity in passing rapidly through the atmosphere constitutes
thunder.
=Lithology= (_li-thŏl´ō-jy̆_).--The science which treats of rocks, as
regards their mineral constitution and classification, and their mode of
occurrence in nature.
=Lode= (_lōd_).--A metallic vein; a longitudinal fissure or chasm filled
with ore-bearing matter and having well-defined side walls; lode, lead,
vein and ledge are synonymous; a mineral vein in the rock.
=Mastodon= (_mas´tō-don_).--An extinct elephant-like mammal of America,
whose teeth have a nipple-like surface.
=Metallurgy= (_mĕt´al-ler-jy̆_).--The art of working metals,
comprehending the whole process of separating them from other matters in
the ore, smelting, refining and parting them; sometimes, in a narrower
sense, only the process of extracting metals from their ores.
=Meteorology= (_mĕ-tē-er-ŏl´o-jy̆_).--The science which treats of the
atmosphere and its phenomena, particularly of its variations of heat and
moisture, of its winds, storms, etc.
=Min´er-al´o-gy= (_mĭn-er-ăl´ō-jy_).--The science which treats of
minerals, and teaches how to describe, distinguish, and classify them.
=Mist= (_mĭst_).--Visible watery vapor suspended in the atmosphere, at
or near the surface of the earth; fog.
=Monsoon= (_mŏn-sōōn´_).--A wind blowing part of the year from one
direction, alternating with a wind from the opposite direction--a term
applied particularly to periodical winds of the Indian Ocean, which blow
from the southwest from the latter part of May to the middle of
September, and from the northeast from about the middle of October to
the middle of December.
=Oceanography= (_ō´shan-ŏg´rȧ-fy̆_).--A description of the ocean.
=Oceanology= (_ō´shan-ŏl´ô-jy̆_).--That branch of science which relates
to the ocean.
=Oreography= (_ō-rē-ŏg´rȧ-fy̆_).--The science of mountains; orography.
=Palæotherium= (_pā-lē-ō-thē´ri-um_).--A tapir-like mammal, having
canine teeth, known only by fossil remains found in Tertiary rocks.
=Pampero= (_pȧm-pâ´rô_).--A violent wind from the west or southwest,
which sweeps over the pampas of South America and the adjacent seas,
often doing great damage.
=Parhelion= (_pär-hēl´yŭn_ or _hē´lĭ-ŏn_).--A mock sun appearing in the
form of a bright light, sometimes near the sun, and tinged with colors
like the rainbow, and sometimes opposite to the sun. The latter is
usually called an _anthelion_. Often several mock suns appear at the
same time.
=Petrology= (_pē-trŏl´ô-jy̆_).--The science which is concerned with the
mineralogical and chemical composition of rocks, and with their
classification; lithology.
=Physiography= (_fiz-e-ŏg´rȧ-fy̆_).--The science which treats of the
earth’s exterior physical features, climate, life, etc., and of the
physical movements or changes on the earth’s surface, as the currents of
the atmosphere and ocean, the secular variations in heat, moisture,
magnetism, etc.; physical geography.
=Plesiosaurus= (_plē-zi-ō-saw´rus_).--An oolithic reptile with
crocodile-like head, known by fossil remains, chiefly vertebræ, found in
lias and oolitic rocks, named from its fossil remains being found near
those of the ichthyosaurus.
=Pneumatics= (_nû-măt´ĭks_).--That branch of science which treats of the
mechanical properties of air and other elastic fluids, as of their
weight, pressure, elasticity, etc.
=Pterodactyl= (_ter-ō-dak´tīl_).--Winged lizard: extinct reptile; fossil
remains found in Kentish chalk.
=Pyroscope= (_pĭr´ô-skōp_).--An instrument for measuring the intensity
of heat radiating from a fire, or the cooling influence of bodies. It is
a differential thermometer, having one bulb coated with gold or silver
leaf.
=Rainbow.=--A bow or arch exhibiting, in concentric bands, the several
colors of the spectrum, and formed in the part of the hemisphere
opposite to the sun by the refraction and reflection of the sun’s rays
in drops of falling rain. Besides the ordinary bow, called also primary
rainbow, which is formed by two refractions and one reflection, there is
also another often seen exterior to it, called the secondary rainbow,
concentric with the first, and separated from it by a small interval. It
is formed by two refractions and two reflections, is much fainter than
the primary bow, and has its colors arranged in the reverse order from
those of the latter.
=Seismology= (_sīs-mŏl´ô-jy̆_).--The science of earthquakes.
=Seismometer= (_sīs-mŏm´e-tẽr_).--An instrument for measuring the
direction, duration, and force of earthquakes and like concussions.
=Simoon= (_sĭ-mōōn´_).--A hot, dry, suffocating, dust-laden wind, that
blows occasionally in Arabia, Syria, and the neighboring countries,
generated by the extreme heat of the parched deserts or sandy plains.
=Sirocco= (_sĭ-rŏk´kô_).--An oppressive, relaxing wind from the Libyan
deserts, chiefly experienced in Italy, Malta, and Sicily.
=Sivatherium= (_siv-a-thē´ri-um_).--A large four-horned antelope, known
by fossil remains found in Pliocene rocks of Hindustan.
=Strophomena= (_strō-fŏm´ĕ-nä_).--A genus of shell-like animals similar
to the nautilus, found in numerous fossil forms in Lower Silurian and
the carboniferous strata.
=Tornado= (_tor-nā´dô_).--A violent whirling wind; specifically a
tempest distinguished by a rapid whirling and slow progressive motion,
usually accompanied with severe thunder, lightning, and torrents of
rain, and commonly of short duration and small breadth; a small cyclone.
=Typhoon= (_tï-fōōn´_).--A violent whirlwind; specifically, a violent
whirlwind occurring in the Chinese seas.
=Wind.=--Air naturally in motion with any degree of velocity; a current
of air.
=Zosterites= (_zos-ter-ī´tez_).--Sear-wracks: marine plants, resembling
sea-weeds, with small naked flowers, found at the bottom of the sea.