Aerodrome.--Literally a machine that runs in the air.
Aerofoil.--The advancing transverse section of an aeroplane.
Aeroplane.--A flying machine of the glider pattern, used in contra-distinction to a dirigible balloon.
Aeronaut.--A person who travels in the air.
Aerostat.--A machine sustaining weight in the air. Aballoon is an aerostat.
Aerostatic.--Pertaining to suspension in the air; the art of aerial navigation.
Ailerons.--Small stabilizing planes attached to the main planes to assist in preserving equilibrium.
Angle of Incidence.--Angle formed by making comparison with a perpendicular line or body.
Angle of Inclination.--Angle at which a flying machine rises. This angle, like that of incidence, is obtained by comparison with an upright, or perpendicular line.
Auxiliary Planes.--Minor plane surfaces, used in conjunction with the main planes for stabilizing purposes.
Biplane.--A flying-machine of the glider type with two surface planes.
Blade Twist.--The angle of twist or curvature on a propeller blade.
Cambered.--Curve or arch in plane, or wing from port to starboard.
Chassis.--The under framework of a flying machine; the framework of the lower plane.
Control.--System by which the rudders and stabilizing planes are manipulated.
Dihedral.--Having two sides and set at an angle, like dihedral planes, or dihedral propeller blades.
Dirigible.--Obedient to a rudder; something that may be steered or directed.
Helicopter.--Flying machine the lifting power of which is furnished by vertical propellers.
Lateral Curvature.--Parabolic form in a transverse direction.
Lateral Equilibrium or Stability.--Maintenance of the machine on an even keel transversely. If the lateral equilibrium is perfect the extreme ends of the machine will be on a dead level.
Longitudinal Equilibrium or Stability.--Maintenance of the machine on an even keel from front to rear.
Monoplane.--Flying machine with one supporting, or surface plane.
Multiplane.--Flying machine with more than three surface planes.
Ornithopter.--Flying machine with movable bird-like wings.
Parabolic Curves.--Having the form of a parabola--a conic section.
Pitch of Propeller Blade.--See "Twist."
Ribs.--The pieces over which the cloth covering is stretched.
Spread.--The distance from end to end of the main surface;the transverse dimension.
Stanchions.--Upright pieces connecting the upper and lower frames.
Struts.--The pieces which hold together longitudinally the main frame beams.
Superposed.--Placed one over another.
Surface Area.--The amount of cloth-covered supporting surface which furnishes the sustaining quality.
Sustentation.--Suspension in the air. Power of sustentation;the quality of sustaining a weight in the air.
Triplane.--Flying machine with three surface planes.
Thrust of Propeller.--Power with which the blades displace the air.
Width.--The distance from the front to the rear edge of a flying machine.
Wind Pressure.--The force exerted by the wind when a body is moving against it. There is always more or less wind pressure, even in a calm.
Wing Tips.--The extreme ends of the main surface planes. Sometimes these are movable parts of the main planes, and sometimes separate auxiliary planes.
