604 INDEX. 



Platina, 467- 



Plato, 183, 581, 682 ; b. 429, d. 348, B.C. 



Pleiades, 395. 



Plempius, 489. 



Pliny, 182, 420, 442, 464, 582 ; b. 24, d. 79. 



Plough, PI. 18. 



Plungers, 253, PL 23. 



Plurality of worlds, 422. 



Plutarch, 183, 184, 458, 582. 



Pneumatic equilibrium, 204, PI. 19. 



Peneumatic machines, 259. 



Pneumatics, 275, 276. 



Pneumatostatics, 196, PI. 19. 



Poetry, 422. 



Polar circles, 436. 



Polarity, 533. 



Polarization of heat, 505. 



Polarization of light, 371, 3?2, 505. 



Poleni, 280; b. 1683, d. 1761. 



Poles, 436. 



Pole star, 394. 



Polished surface, 322. 



Polishing, 176. 



Polycrates, 181. 



Polygon, 20. 



Polygraph, 76. 



Pores, 467. 



Porosity, 360. 



Porterfield, 354, 379. 



Porters, 102, 162, PI. 17. 



Positive electricity, 509. 



Pottery, 171. 



Pound, 96. 



Powder mill, 177. 



Powder proof, 103. 



Powell, 505, 506. 



Power. Mechanical power, 245. 



Practical astronomy, 425. 



Precession of the equinoxes, 402, 412. 



Preponderance, 66, PI. 5, 6. 



Presbyopic sight, 355. 



Press. Bramah's press, 199, PI. 23. 



Presses, 169, 170. 



Pressure, 45. 



Pressure of a fluid, 198. 



Pressure of earth, 124. 



Pressure of fluids, PI. 19. 



Pressure of the atmosphere, 207. 



Prevost, 489, 532, 545, 546, 547, 589. B. Prevost, 



553. 



Priestley, 381, 586; b. 1733, d. 1804. 

 Primary mountains, 439. 

 Printing, 71, 91, 93, 188. 

 Printing from stones, 93. 

 Printing press, 169. 

 Prism, 324, 326, 343, PL 26, 27- 

 Prismatic spectrum, PL 29. 

 Proclus, 186. 

 Procyon, 395. 

 Progressive motion, 100. 

 Projectiles, 17, 26, 29, 217, PI- 2. 

 Projection of a sphere, 90, PL 8. 

 Projection of light, 361. 

 Prony, 284. 

 Proofs, 494. 



Propagation of light, 359. 

 Proper motions of the stars, 392. 

 Properties of matter, 464, 509. 

 Prop or shore, 55, PL 5. 

 Proportional compasses, 79, PL 6. 

 Props of reservoirs, 238. 

 Prosperin, 408. 

 Protagorides, 582. 

 Ptolemaic system, PL 38. 

 Ptolemy, 75, 3?5, 393, 401, 420, 452, 453, 454, 



455, 456 ; fl. 160. 

 Ptolemy Philadelphus, 454. 

 Ptolemy Soter, 454. 

 Pullies, 52, 159, PL 4. 

 Pulse, 220. 

 Pump, 253. 

 Pumping, 102. 

 Pumps, PL 23. 

 Pupil, 354. 

 Pyramids, 454. 

 Pyrometers, 496. 

 Pythagoras, 181, 182, 315, 316, 453, 458, 581; 



b. 568, d. 497, B.C. 

 Pythagorian system, PL 38. 



Quadrant, 80. 



Quadrant electrometer, 527. 



Quadrants, 429, PL 35. 



Quarter, 95. 



Quays, 240. 



Queen post, 130, PL 12. 



Quiescent space, 15. 



Radiation of heat, 488. 



Rafter, 113. 



Rafters in equilibrium, PL 11. 



Railroads, 272. 



Rain, 556, 557- 



Rainbows, 346, 369, PL 29, 30. 



Raising weights, 156. 



Ramelli, 189, 256, PL 23- 



Rammelsberg, 179. 



Ramsden, 80, 86, 97, 336, 338, 381, 461, PI. 7, 8, 

 28 ; b. 1730, d. 1800. 



Range of a projectile, 30, 217. 



Rarefaction, 484. 



Ravenna, 450. 



Ray, 585; b. 1628, d. 1705. 



Ray of light, 320, PL 26. 



Reaction, 42. 



Read, 558. 



Reaumur, 485, 498, 585; b. 1683, d. 175?. 



Reciprocal action, 40, 42, 43. 



Reciprocal force, 470, PL 2. 



Recorde, 375. 



Rectification of motion, 134, PL 14. 



Rectilinear motion, PL 1. 



Redern, 381. 



Red light, 365. 



Red Sea, 449. 



References, 193. 



Reflecting surface, 325. 



Reflecting telescopes, 334, 337, 378. 



Reflection, 62, 342, 361, 374, PL 5, 26. 



Reflection of a stone, 233. 



Reflection of cold, 489. 



Reflection of light, 321. 



Reflection of sound, 293, PL 25. 



Reflection of waves, 219, 293. 



Refraction, 321,322, 361, 375, 430, 433, PL 26, 



29. 



Refraction of crystals, 348. 

 Refraction of the atmosphere, 345. 

 Refractive densities, 323, 329, 375, PL 27. 

 Refrangibility of heat, 490. 

 Refrigeration, 545. 

 Regaforgan pipe, 314, PL 26. 

 Regulation of force, 69. 

 Regulation of hydraulic forces, 241. 

 Regulator, PL 2. 

 Regulus, 395. 

 Reich, 440. 



Relative motion, PL 1. 

 Remote tide, 444. 

 Removing earth, 168. 

 Removing weights, 156, 161. 

 Renaud, 279; b. 1652, d. 1719. 

 Reproduction, 539, 566. 

 Republican calendar, 428. 

 Repulsion, 58, 468, 502, 5<)3, PL 39. 

 Repulsions of floating bodies, 478. 

 Repulsions of the electric fluid, 508. 

 Reservoirs, 238. 

 Resilience, 110, 114, 482. 

 Resinous electricity, 517. 

 Resistance of fluids, 222, 230, PL 21. 

 Resistance of the air, 30,31,154,232, 260, 261, 



284. 



Resistance to the tides, 444. 

 Resolution of motion, 19. 

 Respiration, 575. 

 Retardation, 22. 

 Retina, 351. 



Retrograde motions, 418. 

 Returning stroke, 557- 

 Return of light, 323. 

 Revolutions of cords, 299. 

 Revolving doubler, PL 40, 

 Revolving pendulums, 36, PL 2. 

 Rheita, 334, 376, PL 28. 

 Rhinland foot, 85. 

 Rhythm, 306. 

 Ribaucourt, 76. 



