Page:Dictionary of aviation.djvu/55

 DICTIONARY OF AVIATION 31

pterygoid aspect, an aspect or appearance like that of wings; winglike or winged aspect; specifically, the aspect of an aeroplane or other aerofoil when it presents the appearance (if viewd in the direction of flight) as of some- thing relativly well provided with wings or sustaining* surfaces; also, the appearance of an aerofoil the lesser di- mension of tuhich is in the direction of flight (which is the same as the arrangement which obtains in the wing plan-ferm of birds.

vertical aspect, the aspect of the vertical dimensional proportions, or the elevation, of an aeroplane or other aero- foil; the look or appearance of an aerofoil as viewd in the direction of flight.

aspect-ratio '3e-spekt,zee-$o n. the ratio of the two dimen- sions (in any given aspect) of a natural or artificial flyer; the proportion of the spred, span, or transverse dimension of an aerofoil to its depth, or fore-and-aft dimension.

aspiration ,sesp3'zee-$an n. the action of aspiring or breath- ing; the drawing of breth; specifically, the action of a bird or aerofoil in moving or soaring into the wind, that is, in making hedway or progress against, and relativ to, the wind, apparently by breathing or sucking; a mode of maintaining motion, as if by drawing or polling forward, in flight, in a direction contrary to the wind.

aspirator 'sespa^etaz n. an apparatus for drawing eff air or other gas, and thus creating a partial vacuum.

aspire a'spaiz intr. breath forth; rise, mount up; specifically, move or soar into the wind, that is, make hedway against, and relativ to, the wind, as if by breathing, sucking, or drawing.

astern a'sterzn adv.

1. (of place) in or at the stern or hinder part or end of an airship; in the rear; aft.

2. (of motion) toward the stern; to the rear; aft. astronomy a'stseng-mi n. the science of the stars or hevenly

bodies. atmosphere '3etm3s,fi:z n. [also spelt atmosfere]

1. the sfere of air surrounding the earth; the whole bed} of terrestrial air; the gaseous envelop of the globe; the aerosfere.

2. the air of any particular place or locality, especially as influenced by wether^conditions : as, the *atmosfere of a room, the *atmosfere of Chicago.

3. a pressure of 15 pounds to the square inch, taken as the normal pressure exerted by the air at the surface of the earth : as, a pressure of three *atmosferes.

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