198 DICTIONARY OF AVIATION
signaling-balloon 'signl-irj-b3,loun n. a balloon used for making signals, as in war.
signal-service 'signl,sB:z-vis n. the service or business of transmitting signals; the occupation of signaling, especially in the army : as, to be assigned to *signals;service ; also, an organization for the business of signaling, such as the signakcorps.
silencer 'sai-lan-saz n. a device for silencing or muffling the exhaust of an internal^combustion engin; an exhaust^muf- fler.
silk silk n. cloth made from the fine soft threds of the co- coons of the larvae of bombycid worms cald silkworms, used in making balloon^envelops and other aerial appara- tus.
oiled silk, same meaning as oiUsilk.
simoom si'muum n. a hot, dry sand^wmd occurring in the African and Asiatic deserts in spring and summer.
sine-curve 'sain,kB:zv n. [also spelt sine curve, sinezcttrv] a curv in luhich the abscissa is proportionate to the angle and the ordinate proportionate to the sine of the angle; a curv of sines; a sinusoid.
single-celled ^ingal'seld adj. [also spelt singletceld] having but one cell ; as a cellular kite.
single-surface ,sing3l'sBzfis adj. having a single sustain- ing^surface or aerofoil; having but one aeroplane support- ing^surface : compare doublezsurface.
sink sink n. a hypothetic point or system of points at tuhich a fluid is being destjoyd or absorbd : opposed to source : as, a source?and?*sink system.
sink sink intr. [past participle sunk, sunken', preterit sank, sunk] fall or settle downward, as thru the air, by force of gravity; descend.
sirocco si'zeko n [also spelt scirocco} a hot, dry, often dust^laden southeast spring and summer wind originating in the high lands of Africa and blowing over Malta, Sicily, and Italy : the same as the wind cald in Northern Africa the "leste," and in Spain "la veche."
sirocco-dust si'zeko,dAst n. a sea^dust borne in a sirocco wind.
skid skid n. a sled^like runner attacht to the under surface of an aeroplane or flyingvmachine as an aid in landing; a landing^skid ; a runner.
skid skid intr.
1. slide along after the manner of an automobile the wheels of uuhich are net revolving; slip obliquely thru the
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