136 DICTIONARY OF AVIATION
isohelic ,ai-s3'hii-lik n. an isohelic line.
isohyetal ,ai-sa'hai-i-tl adj. of equal rainfall; marking equal- ity of rainfall ; passing thru points or places on the earth's surface where the amount of rain which falls is the same : as, an *isohyetal line, an *isohyetal chart.
isopag 'ai-s3,p3eg n. a line, as en a wethemnap, which passes thru points or places on the earth's surface where the conditions as to frozen water^surfaces, as of rivers, lakes, harbors, etc., are the same.
isopyc 'ai-s3,pik n. [also spelt isopyk] an isopycnic line; an isopycnic : the inverse of isostere.
isopycnal ,ai-S9'pikNl adj. same meaning as isopycnic.
isopycnic ,ai-s9'pikNik adj. of equal density; marking equality of atmosferic density; passing thru points or places in the earth's atmosfere where the density of the air is the same ; isopycnal : as, an *isopycnic line.
isopycnic ,ai-s3'pikNik n. an isopycnic line; an isopyc.
isostath 'ai-s9,stae9 n. a line which passes thru points or places in the earth's atmosfere where the air has equal buoyancy, due allowance being first made for variation in the force of gravitation.
isostere 'ai-s3,sti:z n. a line which passes thru points or places in the earth's atmosfere where the air has equal spe- cific volume ; an isosteric line : the inverse of isopyc.
isotheral 'ai-s3,6i:-z9l adj. of an isothere or isotheres; of equal mean summer temperature : as, *isotheral lines, an
- isotheral chart.
isotheral 'ai-sa^n-zal n. an isotheral line; an isothere.
isothere 'ai-s3,6i:e n. a line, as n a wether^map, which passes thru points or places on the earth's surface having equal mean summer temperature; an isotheral line.
isotherm 'ai-s3,0B:zm n. a line, as on a wether^map, which passes thru points or places on the earth's surface where the mean temperature is the same; an isothermal line.
isothermal ,ai-s3'9B:z-m9i adj. of equal heat; of the same temperature; marking equality of temperature; isotherm- ous : as, an *isothermal chart, *isothermal relations.
isothermal line, a line, as on a wether^map, which passes thru points or places on the earth's surface where the mean temperature is the same; an isothermal; an isotherm.
isothermal zone, a zone or belt on either side of the earth's equator having the same mean temperature.
isothermal / ai-s3 / 0s:^-m3l n. an isothermal line; an iso- therm.
�� �
