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 DICTIONARY OF AVIATION 75

dart da:et intr. move thru the air like a dart, as a Malay kite; spring or start with a sudden rapid motion; shoot.

date-line 'deet,lain n. the boundary^line between contiguous regions of the globe where the calendar is different; the (practically somewhat devious) nerth^and^south line thru the Pacific ocean (theoretically) identical with the meridian of 12 hours or 180 degrees from Greenwich, Eng- land) east of which the nominal date is one day earlier than en the west of it.

dawn dc:n n. the first appearance of daylight in the mor- ning; daybreak.

false dawn, a transient light, resembling dawn, but ap- pearing about an hour before actual daybreak.

day dee n.

1. the time of sunlight; the interval between the rising and setting of the sun.

break of day, the bursting forth or first appearance of light in the merning; the dawn; daybreak.

clear day, a day in which the sky is clear, see clear sky, under sky.

dark day, any day in which the sunlight is dim or ab- sent, or the atmosfere foggy or smoky, due to prairie or forest fires, volcanic eruptions, etc.

high day, the time when the sun is in the meridian; high noon.

2. the time occupied by the earth in making one complete turn on its axis; the space of twentysfour consecutiv hours.

apparent solar day, the day or interval of time between two successiv meridian transits of the sun.

change of day, a change of one's reckoning in circum- navigating the globe, when, by the calendar, a day is lest or gaind.

gained day, the calendar day which is gaind or reckond twice at the date-line in circumnavigating the globe from west to east.

lost day, the calendar day which is lost or drept out at the date-line, in circumnavigating the globe from east to west.

sidereal day, the interval between two successiv transits of a given star.

daybreak 'dee,bzeek n. the break of day; the first appear- ance of light in the merning; the dawn. day-breeze 'dee,bziiz n. a periodical breeze or light wind

occurring in flat inland regions. day-cloud 'dee,kz,aod n. cumulus cloud; summer^cloud.

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