DECIMAL CLASSIFICATION 
.I5 
208 
154 
I55 
156 
157 
16 
161 
,162 
,163 
164 
165 
166 
167 
17 
I71 
172 
173 
174 
I75 
176 
177 
79 
18 
181 
182 
183 
184 
185 
186 
187 
Aircraft lighter than air Aerostation 
Nondirigible 
Hot air balloons, montgolfiéres; pilot balloons; balloon sonde; kite and 
captiv balloons 
Dirigible Airships oo 
Rigid 
Semirigid 
Nonrigid 
“onstruction 
Gas envelop, material 
Balloon fabrics, netting, gas used, apparatus for inflation 
Car or basket, cabin, seats 
Method of attaching to gas envelop 
Motors 
See 621.4387 
Propellers 
Steering apparatus 
Balancing: gyroscope 
Landing apparatus: anchors, parachutes 
Aircraft hevier than air Aviation 
Kites 
Gliders 
Monoplanes 
Biplanes 
More than 2 planes 
Helicopters 
Ornithopters or orthopters ~~ 
Special adaptations: hydroaeroplanes, aviets 
Construction 
Structure 
Planes, wings, ailerons, etc, 
Seats, cabin, etc. 
Motors 
See 621.4387 
Propellers 
Steering apparatus 
Stability, balancing apparatus 
Starting and landing apparatus 
Applications of aeronautics 
Motor vehicles, automobiles 
Mechanicly propeld and motor vehicles for highways: bicycles, motor cycles 
etc. For highway vehicles for separate tractors (animal or mechanic) see 684. 
Expansion of this subject is in hands of a special committee but has not been 
brought to a stage warranting publication in this edition