INDEX. 



Syllogism, 140; moods of, 55, 84, 

 85, 88, 105, 141 ; numerically 

 defiuite, 1<J8. 



Symbols, use of, 13, 31, 32 ; of 

 quantity, 33. 



Synthesis, 122 ; of terms. 30. 



Tablkturning, 671. 



Tacit knowledge, 43. 



Taequet on combinations, 179. 



Tail, P. G., 375 ; theory of comets, 

 571. 



Talbot on the spectrHni, 429. 



Taitaglia on projectiles, 466. 



Tastes, classification of, 732. 



Tautologous propositions, 119. 



Teeth, use in classification, 710. 



Temperature, variations of, 453. 



Tension of a(iueous vajjour, 500. 



Terms, 24 ; abstract, 27 ; .'ub- 

 stanlial, 28 ; collective, 29 : syn- 

 thesis of, 30 ; negative, 45. 



Terrot, Bisliop, on probabilitj', 212. 



'iVst experinitnts, 347, 433. 



IV'tractys, 95. 



Thales, pi-edicted eclipse, 537. 



Theory, results of, 534 ; facts known 

 by, 547 ; quantitative, 551 ; of 

 exchanges, 571 ; freedom of form- 

 ing, 577 ; of evolution, 761. 



Thermometer, differenlial, 345 ; 

 reading of, 390 ; change of zero, 

 390. 



Theiiiiopile, 3()0. 



Tlmmas, arithmetical macliint!, 107. 



Thomson, Arch])ishop, 50, CI. 



Thomson, James, prediction by, 

 542 ; oil gaseous state, 654. 



Thomson, Sir W., lighthouse sig- 

 nals, 194 ; size of atoms, 195 ; 

 tidi.'S, 450 ; capillary attraction, 

 614 ; magnetism, 665 ; dissipa- 

 tion of energy, 744. 



Thomson and Tait, chronom;'1ry, 

 311 ; standards of length, 315 ; 

 the crowbar, 460 ; polarised light, 

 653. 



Thnmsou, Sir "Wyville, 412. 



'I'huud('r-(:li)ud, 612. 



Tides, 366, 450, 476, 541 ; velocity 

 of, 298 ; gauge, 368 ; atmospheric, 

 367, 553]; 



Time, 220 ; definition of, 307. 

 Toilhunter, Isaac, Jlislmi) of (lie 

 'I'linory of I'roJiahiUlij, 256, 375, 

 '6\)b ; on insoluble ]iroblcni.<5, 757. 



Tooke, Home, on cause, 226. 



Toriicelli. cj'cloid, 235 ; his theo- 

 rem, 605 ; on baromcti'r, 666. 



Torsion balance, 272. 287. 



Transit of Venus, 294, 348, 562. 



Transit-circle, 355. 



Tree of Porphyry, 702 ; of Ramus 

 703. 



Triangle, arithmetical, 93, 182. 



Triangular numbers, 185. 



Trigonometrical survey, 301 ; cal- 

 culations of, 756. 



Trisection of angles, 414. 



Tiining-fork, 541. 



Tycho Brahe, 271 ; on star discs, 

 277 ; obliquity of earth's axis, 

 289 ; ciirumpolar stars, 366 ; 

 Sirius, 390. 



Tyndall, Professor, on natural con- 

 stants, 328 ; nragnetism of gases, 

 352 ; precaution in experiments, 

 431 ; use of imagination, 5("i9 ; 

 on Faraday, 547 ; magnetism, 

 549, 607 ; scope for discovery, 

 753. 



Types, of logical conditions, 140, 

 144 ; of statements, 145 ; classi- 

 fication by, 722. 



Ueberweg's logic, 6. 



Ultimate statements, 144. 



Undistributed, attribute, 40 ; middle 

 term, 64, 103. 



Undulations, of light, 558 ; analogy 

 in thi'ory of, 635. 



Uudulatory theory, 468, 520, 538, 

 540 ; inconceivability of, 510. 



Unique objects, 72.*^. 



Unit, definition of, 157 ; groups, 

 167 ; of measurement, 3U5 ; 

 arcual, 306; of time, 307; 

 space, 312; density, 316; mass, 

 317 ; subsidiary, 320 ; derived, 

 321 ; provisional, 323; of heat, 

 325 ; magnelical and electi'ical 

 units, 326, 327. 



Unity, law of, 72. 



Univer.se, logical, 43 ; infiniteness 

 of, 738 ; lieat-history of, 744, 

 749 ; possible .states of, 749. 



Uranus, anomalies of, 660. 



Vacuum, Nature's abhorrence of, 



513. 

 Vapour densities, 5(>i. ■ 

 Variable, variant, 1 ID, 441, 483. 



3 E 



