616 Our Surroundings 



Anemometer (an-e-mom'e-ter) : An instrument for determining the 

 force or velocity of the wind ; a wind gauge. 



Aneroid barometer (an'er-oid bd-rom'e-ter) : A barometer whose action 

 depends on the changing pressure of the atmosphere upon the flexible 

 top of a metal box from which the air has been largely exhausted. 



Animal: Any living creature, such as a mammal, a fish, a bird, or an 

 insect. 



Annealing (a-neTing) : The process of heating and then cooling a sub- 

 stance, such as glass, to make it less brittle. 



Antenna (an-ten'd) : See aerial. 



Anthracite coal (an'thrd-sit) : A hard, natural coal having high luster. 



Anticyclone (an'ti-si-klon) : A movement of air spirally outward from- 

 a center of high pressure. 



Antipyrin (an-ti-pl'rin) : A narcotic drug made from coal tar. 



Antiseptic (an-ti-sep'tik) : A substance which checks the growth of dis- 

 ease germs. 



Antitoxin (an-ti-tok'sm) : A serum injected into the blood to prevent or 

 cure a disease. 



Anti-trade winds : Masses of air flowing north and south from the belt 

 of equatorial calms, above the trade winds. 



Aorta (a-6r'td) : The large artery that carries the blood from the left 

 ventricle of the heart for distribution to all parts of the body except 

 the lungs. 



Apoplexy (ap'6-plek-si) : Loss of consciousness caused by a blood clot 

 on the brain. It is frequently fatal. 



Apparatus (ap-d-ra'tws) : A device for performing a special work. 



Aquarium (d-kwa'ri-wm) : A water-filled globe or tank, or a building, 

 in which water animals and plants are kept. 



Aqueduct (ak'we-dukt) : A man-made, channel for conveying water. 



Arc light: An electric lamp in which an electric current, by jumping a 

 slight gap between the ends of two carbon rods, produces intense heat 

 and a brilliant light. 



Armature (ar'md-tur) : A soft iron bar placed across the poles of a 

 horseshoe magnet to preserve its magnetic strength ; the iron bar in a 

 telegraph sounder or electric bell which, when attracted by the magnet, 

 causes sounds; a rotating iron core wound with insulated wire, an 

 essential part of a dynamo or electric motor. 



Arteries (ar'ter-iz) : Tubes which distribute the blood from the heart. 



Artesian well (ar-te'zhan) : A well from which water flows or spouts 

 naturally. 



Artificial: The opposite of natural; produced by human labor. 



Aseptic (d-sep'tik) : Free from harmful germs. 



Asphalt: A natural, tar-like, pitchy substance, easily worked when 

 heated. When rolled firm it forms an excellent road surface. 



Asphyxia (as-fik'sT-d) : Apparent death produced by suffocation. 



Aspirin: A narcotic drug made from coal tar. 



Assimilation (a-sim-i-la/shim) : The changing of digested food into liv- 

 ing tissue. 



Astigmatism (d-stig'md-tiz'm) : A defect of the eye due to irregularity 

 in the curvature of the cornea or of the lens. 



Astrolabe (as'tro-lab) : An instrument formerly used in navigation for 

 determining latitude. 



Astronomy (as-tron'6-mi) : The science which treats of the heavenly 



bodies. 

 Atmosphere: The mass of air surrounding the earth. 



