XVI 



CONTENTS. 



Roger Bacon; Clocks ; Engrnving and printing; 246. 

 Leonardo da Vinci; Bacon LordVerulam; Galileo; 

 Napier; 247. Laws of collision; Hooke; Barrow; 

 Newton; 248. FoUowen of Newton ; 249. Modern 



matliematiclans and mechanics; 250. Timekeepers 4 

 Journals; Royal Institution ; 251. Future prospects; 

 Use of a. catalogue of references; 252. Table of the 

 chronology of mathematicians and mechanics; 253. 



PART THE SECOND, HYDRODYNAMICS. 



Lecture xxi. On hydrostatics ; 257. 



Hydrodynamics more dependent on experiment than 

 mechanics; 257. Division of the subject into Hy- 

 draulics, Acustics and Optics; 258. Hydrostatics; 

 Definition of a fluid and a liquid; 259. Surface of a 

 gravitating fluid horizontal; 260. Surface of a re- 

 volving fluid; Pressure of a fluid; 261. Magnitude 

 of hydrostatic pressure ; 262. Hydrostatic paradox ; 

 J63. Blowing with the mouth and lungs; Pressure 

 on the bank of a river ; 264. Pressure on a concave 

 surface ; Pressure of diflferent fluids ; Equilibrium of 

 fluids with solids ; 265. Floating bodies ; 2C6. Sta- 

 biUty and oscillations of floating bodies; Buoyancy; 

 267. Bodies falling in fluids; Hooke's hemisphere; 

 Flexible vessels ; 268, 269. 



Lecture xxii. On pneumatic equili- 

 brium; 270. 



Properties of tlie air, and of gases ; Mercurial co- 

 lumn; 270. Steams and vapours; Weight of the air ; 

 STl.'. Experiments with the air pump; Constitution 

 of the atmosphere; 272. See Corrections. Measure- 

 ment of heights; Ascent of a balloon-; Pressure of 

 the atmosphere; 273. Magdeburg hemispheres ; Na- 

 ture of suction; 274. Barometers; 275. Compres- 

 sibility of liquids; 276. 



Lecture xxiii. On the theory of 



hydraulics; 277- 



General principle of ascending force ; 277. Ber- 

 •nouUi's inferences; 278. ^'elocity of a jet of a fluid ; 

 Ajutages of different kinds; 279. Contraction of a 

 jet; Effect of a short pipe; 280. Diverging pipe; 

 Experiments of Bernoulli, Venturi, and Matthew 

 Young; 281. Discharge through large apertures; 

 Vessels emptying themselves ; 282. Lodss; Siphons; 

 983. Discharge through a vertical pipe; 284. Ex- 

 planation; Limit of velocity; Whirlpool; 285. In- 

 termitting springs; Ascending jets; 286. Oscilla- 

 tions of fluids ; Waves; 287. Reflection of waves ; 

 288; Height of waves; Experimental exhibition of 

 waves; 289. Divergence of waves; Combinations of 

 waves; Applications; 290. Elastic pipes; Circula- 

 tion of the blood; 29 L 



Lecture xxiv. On tlic friction of 

 fluids; 292. 



Experiments of Du Buat; Motions of rivers; 29*. 

 Friction and resist;mce; 293. Examples of the velo- 

 city of- rivers; Velocity at different depths; 294. 

 Weres; 295. Changes and flexures of rivers; Late- 

 ral friction; 290. Ven|uri's experiments; Ball sup- 

 ported by a jet; 297. Discharge of long pipes; Bent 

 pipes; 298. Dilatations of pipes ; Effect of tempera- 

 ture; 299. 



Lecture xxv. On hydraulic pres-. 

 sure; 300.' 



Pressure of fluids in motion; 300. Counterprcs- 

 sure ; Magnitude of the pressure and impulse of fluids; 

 301. Laws of hydraulic pressure; Particular case of 

 ■water wheels; Oblique impulse; 302. Distribution 

 of pressure; 303. Elevation and depression produced 

 by the motion of a floating body; Form of a ship> 

 Body moving below the surface; 304. Convex sup- 

 faces; Hydraulic pressure of the air; 305. Concave 

 surfaces; Great effect of an increase of velocity; 

 S06. Reflection of a ball or stone ; 307. 



Lecture xxvr. On hydrostatic in- 

 struments, and hydraulic archi- 

 tecture ; 308. 



Statics and architecture of fluids; Hydrostatic ba- 

 lance; 308. Hydrometer; Glass globules; 309. Spe- 

 cific gravities of particular substances; Mixtures; 

 Spirit level; 310. Hydrostatic lamps; 3]1. Fjo- 

 bmikments; Dil^es: Rivers; 312. Reservoirs; Flood 

 gates; 313. . Strength of sluices and flood gates; 

 Friction; 314. Canals; Pirrs; Harbours; 315. 



Lecture xxvir. On the regulation 

 of hydraulic forces; 316. 



Machinery of fluids; Watcrpipes; Siphons; 310. 

 Stopcocks and valves; 317. Pitol's tube ; Hydromc" 

 trie fly; Captain Hamilton's hydraulic register; 318. 

 Motions of the air; Weight and impulse of Jluids; 

 Raising weights by the descent of water ; 319. Effect 

 4>{ velocity ; Overshot wheel ; 030. Undershot wheel ; 



