INDEX. 



ABACUS, the logical, i. 119; Briggs', 

 206. , 



Abecedarium, the logical, i. 109, 214, 

 234; ii. 367, 380,387. 



Aberration of light, ii. 169, 185. 



Abscissio infiniti, i. 94 ; ii. 400. 



Abstract terms, i. 33 ; numbers, 357. 



Abstraction, logical, i. 30; ii. 389; 

 numerical, i. 177, 215 ; of indifferent 

 circumstances, 112. 



Academic del Cimento, ii. 36, 42, 46. 



Accident, logical, ii. 378. 



Accidental discovery, ii. 162. 



Achromatic lenses, ii. 42. 



Actinometer, i. 389. 



Agassiz, ii. 416. 



Airy, Sir George Biddel, ii. 171, 174, 

 190, 196 ; perpetual motion, i. 257 ; 

 accidental discovery, 267 ; density of 

 earth, 340 ; ii. 209 ; pendulum, i. 

 355 ; errors of observation, 459; tide 

 wave, ii. 1 1 1 ; extrapolation, 1 20. 



Alchemists, ii. 37, 133. 



Algebra, i. 141, 174, 185. 



Algebraic geometry, ii, 290. 



Allotropic condition, ii, 331, 340, 341. 



Alloys, number of, i. 218 ; properties of, 

 ii. 161. 



Alphabet, permutations of, i. 196, 203. 



Alphabetic indexes, ii. 401. 



Alternative relation, i. 80. 



Ampere, electricity, ii. 184; classifica- 

 tion, 351. 



Anagrams, i. 146. 



Analogy, ii. 244, 283 ; in sign of equality, 

 i. 1 8 ; use of, ii. 140 ; use in discovery, 

 286 ; in mathematics, 288 ; in theory 

 of undulations, 293 ; in astronomy, 

 297 ; failures in, 302. 



Analysis, logical, i. 140. 



Andrews, Dr., ii. 266, 334. 



Antecedent defined, i. 258. 



Anticipation of nature, ii. 137. 



Apparent equality, i, 319 ; sequence of 

 events, ii. 13. 



Approximation, principles of, ii. 92 ; to 

 exact laws, 79. 



Aqueous vapour, ii. 126. 



Aquinas, ii. 384 ; on logical division, i. 



82. 

 Arago, photometer, i. 335 ; rotating disc, 



ii. 170, 240. 

 Archimedes, de arenas numero, i. 222 ; 



centre of gravity, 422. 

 Aristotle, dictum, i. 26 ; overlooked 



simple identities, 46, 48 ; imperfect 



syllogistic conclusion, 7* > on time, 



359- 



Arithmetic, reasoning in, i. 188 ; of ap- 

 proximate quantities, ii. 103. 



Arithmetical triangle, i. 108, 208, 230. 



Asteroids, discovery of, ii. 1 7, 444. 



Astronomy, i. 285 ; ii. 201. 



Atmospheric tides, ii. 192. 



Atoms, ii. 10; size of, i. 222 ; weights 

 of, 205. 



Augustin, on time, i. 359- 



Aurora, i. 322. 



Average, i. 417 ,' divergence from, 213 ; 

 derivation of word, 421. 



Axes of crystals, ii. 359. 



Axioms of algebra, i. 185. 



B. 



Babbage, Charles, ii. 455; calculating 

 machine, i. 123, 437 ; lighthouse sig- 

 nals, 220; change of law, 265; ii. 

 437 ; natural constants, i. 381 ; hu- 

 man remains, ii. 17; general prin- 

 ciples, 309. 



Bacon, Francis, biliteral cipher, i. 220; 

 on causes, 254 ; Copernican system, 

 287; instances, 313; the senses, 322; 

 fallacies, ii. 5 ; method of, ii. 134, 

 220; use of hypothesis, 137; experi- 

 mentum crucis, 149; latens proces- 

 sus, 273. 



Bacon, Roger, on rainbow, ii. 159, 247. 



Baily, Francis, i. 316; ii. 171; pen- 

 dulum experiments, i. 463; experi- 

 ments on density of earth, i. 430, 

 462 ; ii. 41, 208. 



