Defn: An imaginary line, or a line on a chart, marking the simultaneous development of a thunderstorm, as noted by observing the time when the thunder is heard at different places.
ISOCEPHALISM
I`so*ceph"a*lism, n. Etym: [From Gr. Iso-, and Cephalon.] (Art)
Defn: A peculiarity in the design of bas-relief by which the heads of human figures are kept at the same height from the ground, whether the personages are seated, standing, or mounted on horseback; — called also isokephaleia.
ISOCHASM
I"so*chasm, n. Etym: [Iso- + chasm.] (Phys. Geog.)
Defn: A line connecting places on the earth's surface at which there is the same mean frequency of auroras.
ISOCHASMIC
I`so*chas"mic, a.
Defn: Indicating equal auroral display; as, an isochasmic line.
ISOCHEIM
I"so*cheim, n. Etym: [Iso- + Gr. (Phys. Geog.)
Defn: A line connecting places on the earth having the same mean winter temperature. Cf. Isothere.
ISOCHEIMAL; ISOCHIMAL
I`so*chei"mal, I`so*chi"mal, a.