INDEX 



The Figures refer to the sections. 



ABERRATION of light, 108 

 Absolute Zero, 68 

 Absorption and radiation, 63 

 Absorptive power of air, 160 

 Abysmal area, 255, 257, 277 

 Accuracy, 10 

 Acids, 44 



Adelsberg caves, 317 

 Adriatic Sea, 216, 325 

 Africa, 373'377. 412 

 Agassiz, Lake, 368 

 Agonic lines, 98 

 Agulhas current, 248 

 Air, 151 ; in sea- water, 225 ; 

 temperature of, 187, 189, 190 

 Albert, Lake, 375 

 Aletsch glacier, 337 

 Alluvial deposits, 322 

 Alps, 303, 385 

 Altai Mountains, 381 

 Altitude of the Sun, 124 

 Amazon, 219, 230, 269, 318, 



319. 36i 

 America, see North, and South 



America. 



American race, 424 

 Amu Daria (Oxus), 382, 432 

 Amur River, 319, 381 

 Analysis, 40 ; spectrum, 63 

 Andes, 201, 353, 358 

 Anemometer, 442 

 Aneroid barometer, 439 

 Angles, 31 et seq. 



Angular measurement, 31-33 



Animals, 397, 400, 409-417 



Antarctic circle, 122 



Antarctic continent, 276, 340 



Anthracite, 347 



Anticlines, 302, 303 



Anticyclones, 205 



Anti-trade winds, 181 



Apennines, 385 



Appalachian Mountains, 366 



Approximation, 10 



Arabia, 379, 412 



Aral, Lake, 333, 382 



Arbour Day, 434 



Archaean rocks, 346 



Arctic circle, 122 ; sea, 216, 234 



Aryans, 425 



Ash, volcanic, 294 



Asia, 379-383 



Asteroids, 129 



Atlantic Ocean, 216, 243-246, 



258 .. 



Atmosphere, 84, 145-213 

 Atmospheric electricity, 172 

 Atolls, 280 

 Atoms, 47, 48 

 Aurora, 99, 174 

 Austral group of plants, 405 

 Australia, 353, 370-372 

 Australian people, 423 ; realm, 



4i5 



Autumnal equinox, 123 

 Avalanches, 336 



