THE STEAM-ENGINE. 



(THIRD LECTURE.) 



Methods of Connecting the Piston-Rod and Beam in the Double-acting Engine.— Rack and Sector. 

 — Parallel Motion. — Connexion of Piston-Rod and Beam. — Connecting Rod and Crank. — Fly- 

 Wheel. — Throttle- Valve. — Governor. — Construction and Operation of the Double acting Engine. 

 — Eccentric. — Cocks and Valves. — Single-Clack Valves. — Double-Clack Valves.— Conical Valves. 

 — Slide Valves.— Murray's Slides.— The D Valves.— Seaward's Slides.— Single Cock.— Two- 

 way Cock. — Four-way Cock. — Pistons. — Common Hemp-packed Piston. — Woolf s Piston. — Me- 

 tallic Pistons.— Cartwright's Engine. — Cartwright's Piston. — Barton's Piston. 



