DICTIONARY OF AVIATION 167
pansion so as to enable the animal to take flying leaps; the wing^membrane of a bat; a parachute.
2. a fold or integument occupying the angle between che upper arm and the forearm of a bird.
3. one of a pair of processes or appendages en the pro- notum and thorax of certain leptideptera.
pa til- curvature 'pa:0,kB:z-v3-t$9z: n. the curvature of the
flightepath of a flying aircraft. patrol p9'tDol tr. tjavers, or move about in, as if en duty
or en the watch; tjavers leisurely in all directions: as,
- patolling the sky.
peace-bomb 'piis,bem n. [also spelt peacetbom} a bem^like
missil used for peaceful purposes; one of the medaklike
disks drept from a friendly airship, intended as a symbol
of peace, or as an advertisement, destind to be pickt up and
kept as a souvenir by the people upon the earth below. pear-shaped 'pe:z,$eept adj. having the shape or ferm of a
pear, as certain balloons or gasbags. pectoral 'pekt9-zal adj. ef, pertaining to, or situated en, the
brest or chest of a bird or other animal, or some part or
region of a flymg-machine likend thereto; thoracic: as,
- pectoral fins, *pectoral muscles.
pedal 'pedl n. a device, as in a flyingsmachine, which is
actuated by the foot of the operator; a footelever; a tjedle. pedal 'pedl, 'pii-dl adj. ef or by means of the foot: as,
- pedal control.
pegamoid 'peg9,meid n. a parchmentelike material used en
the outside of balloon?envelops for protection from the sun,
rain, etc. pegasidae pi'gsesi,di n. pi. a family of fishes, typified by
the genus Pegasus; the flying sea-horses.
pendulum 'pendsu-tem n. a bedy suspended in such a man- ner as to siuing freely to and fro under the influence of
gravity and its energy of position. The pendulum has been
suggested as a means of automatic balance for flying?
machines.
penna 'pens n. [ploral pennae] a centour^f ether ; a pluma. pennant-line 'pen9nt,Jam n. the line or cerd connecting a
branch kite with the main kite-line. pennipotent ,pe'mp9-tnt adj. strong en the wing; powerful
in flight. percaline 'pB<rk9-!m n. [also spelt percaliri} a glossy French
cetton cleth, sometimes used for kite^sails. pereher 'pi3zt$9z n. a bird which habitually perches, as dis-
tinguisht from birds which rest on the ground; a perching
bird.
�� �