Zeta Herculis, periodic time, eclipse
of, 398 ; light, 402.
Zinc, seleniate of, effect of tempera-
ture on its crystals, 107; sulphate
of, its crystals boiled in alcohol,
electricity communicated to
plates of, 220.
Zodiac, the, signs of, change in their
Zone of constant temperature in the
atmosphere, 119; laws of storms
in the temperate and torrid, 127,
128 ; of spots on the sun's surface,
its breadth, 224; of constant tem-
perature below the earth's crust,
228 ; comparative unequal distri-
bution of land in temperate and
torrid, 244 ; of fixed stars, 385 ;
of stars nearest the sun, 390 ; ne-
bulous, 416 ; of nebulous patches,
417; of meteoric nebulæ, 423.
Zones of instability of planetary orbits,
of temperature in the ocean,
of vegetation on the Peak of
Zoophytes, specific distribution of,
LONDOX: PRINTED BY W. CLOWES AND SONS, STAMFORD STREET,
AND CHARING CROSS.