I. 3 ] 



Egyptian calendar, period of the 

 complete arrangement of the, 179. 



Ehrenberg, on the incalculable num- 

 ber of animal organisms, 35. 



Electrical light, velocity of trans- 

 mission of, 114. 



Electricity, transmission of, through 

 the earth, 117. 



Elements, Indian origin of the 3V 

 pothesis of four or five, 9. 



Emanations from the head of some 

 comets, 47. 



Encke, his accurate calculation of 

 the equivalent of an equatorial 

 degree, 107 ; on the star- maps of 

 the Berlin Academy, 156 ; an 

 early calculator of the orbits of 

 double stars, 287 ; his theory of 

 their motion, 288. 



Encke's comet, considerations on 

 space, derived from periods of 

 revolution of, 36 ; a resisting 

 medium proved from observation 

 on, 47. 



Ether, different meanings of, in the 

 East and the West, 36, 37. 



Ether (Akd'sa, in Sanscrit), one of 

 the Indian five elements, 36. 



Ether, the, fiery, 42. 



Euler's comparative estimate of the 

 light of the sun and moon, 177. 



Fixed stars, the term erroneous, 30, 

 164; scintillation of the, 96 ; va- 

 riations in its intensity, 101 ; our 

 sun one of the fainter fixed stars, 

 127; photometric arrangement of, 

 132; their number, 141 ; number 

 visible at Berlin with the naked 

 eye, 143 ; at Alexandria, 144 ; 

 Struve and Herschel's estimates, 

 157 ; grouping of the, 157 ; distri- 

 bution of the, 189 ; proper motion 

 of the, 248; parallax, 256 ; num- 

 ber of, in which proper motion 

 has been discovered, greater than 

 of those in which change of posi- 

 tion has been observed, 281. 



Fizeau, M., his experiments on the 

 velocity of light, 107, 110. 



Formula for computing variation of 

 light of a star, by Argelander, 228. 



Galactic circle, average number o r 

 stars in, and beyond the, 188. 



Galileo indicates the means of dis- 

 covering the parallax, 256. 



Galle, Dr., on Jupiter's satellites, 

 64 ; on the photometric arrange- 

 ment of the fixed stars, 132. 



Garnet star, the, a star in Cepheus, 

 so called by William Herschel, 

 225. 



Gascoigne applies micrometer 

 threads to the telescope, 52 



Gauging the heavens, by Sir William 

 Herschel, 187 ; length of time 

 necessary to complete the pro- 

 cess, 187. 



Gauss, on the point of translation 

 in space of the whole solar sys- 

 tem, 266. 



Gilliss, Lieutenant, on the change 

 of colour of the star rj Argus, 

 183. 



Gravitation, not an essential pro- 

 perty of bodies, but the result of 

 some higher and still unknown 

 power, 24. 



Greek sphere, date of the, 160, 162. 



Green and blue suns, 283. 



Groups of fixed stars, recognised 

 even by the rudest nations, 157; 

 usually the same groups, as the 

 Pleiades, the Great Bear, the 

 Southern Cross, &c.', 158. 



Halley asserted the motion of Sirius 

 and other fixed stars, 30. 



Hassenfratz, his description of the 

 rays of stars as caustics on the 

 crystalline lens, 66, 171. 



Heat, radiating, 41. 



Hepidannus, monk of Saint Gall, 

 a new star recorded by, 213, 220. 



Herschel, Sir William, on the vivi- 

 fying action of the sun's rays, 40; 

 his estimate of the number of the 

 fixed stars, 157; his "gauging 

 the heavens," and its result, 187. 



