450 



INDEX. 



Numbers refer to Paragraphs. 



Polariscope, 672. 

 Polarization, Electric, 341. 



" of light, 667-673. 



Poles, Magnetic, 304, 306, 317. 

 Polygon of forces, 89. 

 Porosity defined, 42. 

 Porte-lumiere, page 376 (note). 

 Potassium bi-chromate battery, 383. 

 Press, Hydrostatic, 223. 

 Pressure, Atmospheric, 273, 275, 277. 

 " Downward, 225, 226. 

 u Lateral, 230, 231. 

 " Transmission of, by liquids, 



216. 



" Upward, 227, 228. 

 Prince Rupert drops, App. D. 

 Principal axis, 599-623. 



" focus, 599, 601, 624. 

 Prisms, 62 1. 

 Projectiles, 133. 



Path of, 135. 

 " Time of, 136. 



Proof-plane, 340, 358. 

 Propagation of sound, 422. 

 Properties, Characteristic, 19, 21. 

 u Chemical, 15. 

 " of matter, 13. 

 " Physical, 14, 15. 



" Universal, 18, 20. 

 Pulley, 192, 197. 

 Pump, Air, 288, 293. 

 il Force, 296, 297. 

 " Lifting, 294. 



Q, 



Quality of sound, 464. 



R 



Radiation and absorption of heat and 



light, 654, 655. 



Radiation of sound, 542, 545. 

 Rainbow, 641-645. 

 Random, 134. 

 Range, 134. 

 Rays of light, 582. 

 Reaction, 72, 93, 94, 95. 

 Reed pipes, 470. 

 Reflected motion, 96, 97. 

 Reflecting telescope, 662. 

 Reflection of heat, 554. 

 light, 590. 



" sound, 440. 



" Total internal, 616. 



Refracting telescope, 661. 

 Refraction, Double, 673. 



" of heat, 556. 



Index of, 613. 



" of light, 612. 



" " sound, 438. 



Refractors, Kinds of, 619, 

 Reinforcement of sound, 449. 

 Repulsion, Electric, 324. 

 Resistance, Electric, 378. 

 Resolution offerees, 91, 199. 

 Resonance, 450. 

 Resultant motion, 79, 85. 

 Rivers, Flow of, 258. 

 Ruhmkorff's coil, 410. 



S 



Safety-valve, 575. 

 Scale, Musical, 456, 457. 

 Science defined, i. 



" Physical, 9. 

 Screw defined, 208. 



" Endless, 210. 



" Law of, 209. 

 Secondary axis, 599, 623. 

 " foci, 624 (3). 

 Selective absorption, 553. 

 Sensible heat, 516. 

 Shadows, 586. 

 Siphon, 298-300. 

 Smee's battery, 382. 

 Solar spectrum, 635. 

 Soldering, App. B. 

 Solid defined, 54, 6t. 

 Sonorous tubes, 466. 

 Sound beats, 452, 453. 



" Cause of, 421. 



" defined, 415. 



" Focus of, 439. 



" Interference of, 451. 



" media, 424. 



" Propagation of, 422. 



" Quality of, 464. 



" Reflection of, 440. 



" Refraction of, 438. 



" Reinforcement of, 449, 



u Velocity of, 425-427. 



" waves, 423. 

 Sounding-board, 444. 

 Spark, Elec ric, 3 6 4> 37 1 ( 2 4) 

 Speaking-tubes, 433. 

 Specific gravity defined, 241. 



