INDEX 



53; clusters, groups, and 

 streams, 54, 97; the group of the 

 big dipper not a permanent ar- 

 rangement, 55; the two great 

 streams discovered by Professor 

 Kapteyn, 56 ; how they are 

 weighed, 91; double, discovered 

 by Sir William Herschel, 92; 

 double, their change of mutual 

 position makes it possible to 

 calculate their mass, 93. 



Star fish, two or more eggs of, 

 fused to form a single embryo 

 by Professor Loeb, 149. 



Star groups, some interesting ex- 

 amples, 97. 



Stegomyia, mosquitoes of this 

 genus transmit yellow fever, 

 249. 



Stokes* law, utilized in the count- 

 ing of electrons, 128. 



Struggle for existence, illustrated 

 in its application to evolution, 

 179. 



Sub-marine vessels, their inven- 

 tion and development, 287. 



Sun, moves at a rate of about 

 12 ^ miles per second, 38; the 

 direction of its flight ; it is mov- 

 ing toward Vega and away from 

 Sirius, 43; its annual flight car- 

 ries it almost double the diam- 

 eter of the earth's, 44; as com- 

 pared with the neighboring 

 stars, 53 ; how it is weighed, 70 ; 

 the transit of Venus method of 

 determining its size not satis- 

 factory, 75 ; its parallax cannot 

 be determined with accuracy 

 from direct observations, 74; its 

 distance determined by various 

 methods, 72; its parallax not 

 far from 8.807 seconds and its 

 distance known within about 

 30,000 miles, the figure being 

 not far from 92,897,000 miles, 

 80; its corona explained by Ar- 

 rhenius as due to light pressure, 

 112. 



Sun spots, shown by Professor 

 George E. Hale to have magnet- 

 ic fields and to reveal the Zee- 

 man effect, 105. 



Syphilis, a specific found in sal- 

 varsan, 230 ; the germ of, dis- 

 covered by Schandinn and Hoff- 

 mann, 234. 



Telautograph, Professor Korn's 

 apparatus for sending pictures 

 by wire, 316. 



Telectograph, Mr. Baker's appara- 

 tus for sending pictures by wire 

 and by wireless, 316. 



Telegraph, the wireless, 305. 



Telescope, the largest examples, 

 33; revelations of small and 

 large, 35; the Mt. Wilson re- 

 flector reveals stars of 20th mag- 

 nitude, 35; the Paris refractor 

 the biggest of its type, 33. 



Thomson, Sir J. J., explains the 

 seeming transmutation of ele- 

 ments in the laboratory, 124; 

 finds a new substance apparent- 

 ly having atomic weight 3, pos- 

 sibly a new element, 124; his 

 estimate of the activities of the 

 electron, 130; his theory that 

 the electron is the source of 

 ether waves constituting radiant 

 energy, 133; his estimate of the 

 density of the ether, and of the 

 porous character of matter, 135. 



Thompson, Dr. Wm. H., his esti- 

 mate of vaccine therapy, 209. 



Thorium X, its physiological and 

 remedial effects, 235. 



Tidal influence, as determining 

 the shape of nebulae, 18. 



Time and Space, the conquest of, 

 Chapter X, 279. 



Tissues, living, grown outside the 

 body by Drs. Harrison, Carrel, 

 and Burrows, 165. 



Top, working wonders with a, 

 Chapter IX. 255. 



Tower, Prof. W. L., his experi- 

 ments with the eggs of beetles, 

 185. 



341 



